I think its definitely worth an effort to try a silent protagonist, just to see how things pan out.
One game worth noting, that many of this generation may not have played, Chrono Trigger. The first time I played it, I didnt realize that the main character was completely silent! I think what happened was the story was told in such a way that the "voice" of the character, or more to the point, the lines of text were replaced by requiring the Player to perform the actions of that text. For example, in the beginning when meeting the first character, the "text" of "here is your pendant" is replaced by Player acting out the return of the pendant. The text involved in that scene comes from the other character, something like "thank you for returning my pendant" which allows the Player to feel as if they were the ones interacting with the other character instead of controlling a Sprite on a screen.
Slightly off topic.
Learning from failures. Such as Syfy channel movies. Those movies are typically considered to be absolutely terrible. Ive seen enough that I study for patterns in the way they tell their stories. There is typically a set of stereotype characters. Kids are always hackers. Captain Coffee: the Commander in Chief that knows nothing about the tech at hand, just barks out orders for some subordinate to "get it done". The first character introduced is usually nameless and dies during the reveal of the monster or naturally occuring threat to others. The unlikable protagonist. The useless military or police presence that do not listen to the warnings issued by the protagonist. The supporting cast is completely irrelevant and the story many times would occur with or without their involvement, and are just along for the ride.
What Ive noticed from the total failure of Syfy channel movies is that their dialogue is amost always Situational based. "We need to get from here to there". They basically spew objective information: The volcano is a threat, the monster is a threat, we can survive / win if we...". Its almost always a reaction to the situation. Warn others. Quick, get out of the car before the electromagnetic shockwave kills us. Phew, that was close. Oh look, such and such supporting character is dead.
What they do not do is to react to the other characters. Authority never listens to those who see the initial problem. Those characters are going to have their own unique relationships with each other, just as the Viewer (player in games) is expected to have with the Protagonist. They forget that Captain Coffee doesnt just have a relationship with his subordinates and Protagonist, but the other supporting cast. The other supporting cast will have other types of reactions and relationships with everyone else. These things are nearly never defined. In a movie, there is rarely time to have more than one or two lines of dialogue between every cast member involved. A cast of 5 characters means there needs to be 25 lines to define those relationships. So those lines are written to be as impactful as possible and not take three hours to explain that so and so are lovers. I think that for important relationships, main characters, or groups of characters need this.
In context of a game, those lines are what define the Players expected relationship with each other important character. These lines doesnt need to be a spoken line by the Players character, as is the case where the other character both explains what the Player / Protagonist did, and shows a reaction to those actions. "Thank you for returning my pendant." Its a reaction that accoplishes both explaining and keeping the Players character from stating the obvious, which is where I think dialogue gets boring.
The situational dialogue I think is best reserved for non party characters, such as townsfolk, but they need to react to the situation. "The volcano is going to erupt because of the Dragon!" Yeah, okay, so why are you standing around with your thumb in your ass? "Im going to move to another down because the Dragon in the volacano will make it erupt!" Standing around there is acceptable because that character shows a reaction and intent to leave. Its a bit more than two dimensional. The two dimensional character is one that states only the obvious without having ANY reaction to an obvious situation. Those are the super boring dull characters that are completely hated by most people. And since many stories are told in RPG's through the dialogue of the situational responsive characters, the less they react to that situation, the less impact the story will have on the player.
"I hope daddy can do something about the dragon in the volcano!" It explains what needs to be the Players next objective as well as showing that characters reaction to that situation. Really, that dialogue is still very dry. "Im terrified that the Dragon in the volcano will make it erupt!" I bit more emphasis on that characters reaction to the situation. The abbreviation of text keeps the player from getting bored by providing double meaning. Both a reaction and explanation of what they are reacting to. Its not appropriate in all cases, but look at Syfy and why their movies suck so bad! They dont react, just state the obvious.
Sometimes, this is all heavily related to Scripts. One of the scripts I worked on modifying heavily was Wachungas Multiple Message Windows. One of the technical reasons for this was a storytelling style, where if the Player is to be offered a choice, that "Choice" needs to come from the Players character. So, something simple "Do you want to buy something?" would show a second Dialogue Bubble that originates from the Players character "Um... [Sure! / Not right now...]" Its very simple, but reinforces the idea that the Player controls the Protagonist and defines who they are expected to project on to. The choice of buy or dont buy doesnt define the Protagonist as any specific personality archtype by replacing their dialogue with what the Player decies the characters need. This is Projection of the Player on to the Protagonist and helps to build that relationship, and how Scripts are useful to accomplish this.
One of the other things I did with the Scripts that support Storytelling was to reinforce the idea that the Player can "walk away" from an NPC with too much dialogue. The more the Player feels like they are "in control" of the Protagonist helps with that Projection. When townsfolk NPCs trap the Player into long dialogue, the Player may feel like they are NOT in control and it undermines that Projection. And from a technical aspect, I think that technical cause is why many RPG Maker games fail. Take a look at Chrono Trigger again. The Player is allowed to walk away from many NPCs when they talk. During cutscenes, some actions are controlled by the game. They had this absolutely right many many years ago, but we didnt catch on to why the Player was allowed to walk away. Now not every game does this, but how many successful first tier games did allow this?
Much of this is my choice of style and it wont be appropriate in every game out there. But if you want to see how this style works, my "
Collection of Art and 100% Compatible Scripts" is over in the XP Scripts section. It took me a long time to develop that "Style". The first script I ever did was Zeriab's Caterpillar, upon which I based my Caterpillar. The Caterpillar dialouge is also contained in that "Collection" but also shows the evolution of characters being "forced" into long script explanations that traps the Player. There are a bunch of Maps in the "Collection", each built with the idea of teaching how to use a specific Script. Later scripts and maps allow the player to just "walk away" while the earlier stuff "traps" the Player. So both styles are there. As its a Tech Demo and not really a game, I didnt mind having inconsistent styles.
It may sound like I am pumping my own stuff, again, which I do have a tendancy to do, but try to do so with valid reasons. The point isnt to promote my own stuff, but to show how Technical things like Scripts can either hold a game back or help the Player to build and maintain that sense of Projection onto the Protagonist.
One of the other things I feel that is sorely lacking in RM, some due to technical limitations, is efforts to tell stories through Body Language. More than 90% of what we communicate is Non Verbal. During important Cutscenes, the movement of Sprites around the screen conveys that Body Language. Chrono Trigger, again, is a prime example of this. Although the main character did not speak, he told you how he is "feeling" by reacting to the dialouge and situations with Body Language. There were a ton of different poses and sprites for Chrono as well as the other important characters. We dont have many different poses other than just a "walk animation" for 99% of our RM characters. That makes it difficult for us to use body language to tell our stories. But we dont have to literally animate and sprite out every single pose a character can use in a game. Again, my own stuff, MMW has a feature to make a character change their poses as dialogue appears on the screen. That little stuff adds greatly to a characters body language. And the reason I did it in a script was because the Player can walk away, which makes directional based poses an absolute nightmare to event out, but easy as three characters in script. "Can I have that?\F+" where as soon as the statement finishes, while the dialogue is still up on screen, that character asking will change their "foot" and "reach out" to be given what they are requesting. Body Language.
In summary, although a Protagonist may be complely or almost completely silent, they can still be made to be complex characters through their Body Language. Rushing to offer aid to a character the Protagonist cares deeply about, or turning their back when they are experiencing self conflict. Chrono was one of those characters who told his story through his Body Language with very little dialogue. Gordon Freeman was not as the Player was always in control of where Gordon was looking. Although a character may not speak, they can convey what they think and how they feel non verbally, or non-texually. I think that generally, those types of reactions that a Protagonist may be given with Body Language conflicts less with the Players personality than a text based response. I know Im blathering, but hopefully some of this is useful to anyone that reads my longwinded posts...