Superior numbers press forward with crowd pressure after busting doors down and can rapidly crush and kill all inside. Fighting a way in with cold steel should not be all that problematic if you have the numbers. If garrisoning is permitted it must be made more realistic. (3) Garrisoning was a problem as outlined by Nowy.
After that, the player should be able to run his economy almost automatically, without thinking much about it, so he can give almost his full attention to battles, tactics and strategy. I believe that an RTS economy should take a certain amount of learning and competence. The whole feel of the artwork is rough and messy. Go back and look at how well the buildings and ships are done. The artwork in C1 was of an excellent quality. Here are my reasons and some might overlap with reasons given above. No doubt, everyone has their reasons and theories why AC did not do so well.
