the following information stems from the internet (tm) and is thus utterly 100-% correct.

buildings have exactly one sprite
	exception: e.g. town center, which has multiple sprites for different sections (walkable...)

units have 5 states: idle, walking, attacking, dying, rotting. for each state, there is a sprite for every direction the unit could be facing
	exception: villagers, ofc, have a lot more states
	ships have extra sprites for their sails