my big problem in siege is that a lot of maps are made for native and not for crpg, which means that in crpg the attackers will have a lot bigger chance of winning a round, and that's mostly because of ladders. if in a maa there are 2 ladders, that's reasonably defendable, but in crpg that means there are going to be put atleast 2 more ladders up, so half the chance that the defenders are going to win, only if the attacker team doesn't use the key spots on the map and there are 15 clan people on the defending side, the defenders have a shot at winning.
so my point is that the maps should be re-looked at, because by just adding a few doors more, making surtain rooftops unreachable or removing a ladder would balance the difference between defenders and attackers, it wont solve all the imbalance, but it would help atleast.