I added this feature request today, as it puzzled me why the tilemap was unable to properly z-sort tiles, which renders it unusable for pseudo 3D perspectives like Pokèmon and such. Right now, as tilemaps work, it’s impossible to do draw bushes and trees like these in front of characters (see those rats) using only tilemaps:
Reason being you need to z-sort tiles too, as fixed z coordinates (like tilemap layers have) are not enough.
A temporal solution is using sprites for all props and tilemaps just for ground tiles, but I guess it would simplify things quite a lot if tilemaps would be able to z-sort tiles individually.