Yeah to do stuff like that it's a little tedious, but easily doable. Roughly speaking, if you hold shift and right-click when you select a part of the map (you can drag to get more than one tile), then you can repaste that exact piece wherever and as much as you want by holding shift and left-clicking.
So, all you need to do is make each of the pieces you want individually, and copy and paste them into a group using that method.