TileE has a set number of tiles that you can actually use.
TileE is a 16x16 grid each grid block is the size of 32x32 pixels.
Also take note that
A: The first 8 columns of the grid will be shown as the first tiles in the editor of the game. Columns 9-16 get pushed below those so if you make your tile-set horizontally as you add tiles, it will appear distorted in the editor of the game, but that is just for your convenience.
B: TileE has the same pass-ability as TileD.
So to answer your question. Yup. Trying to cram all the other tile-sets into tileE will not work.