So is a besieging army supposed to automatically damage and therefore disable all the buildings in a settlement?

[Enosu]

Playing as Macedon and destroyed the Byzantines but for some reason their general survived even though I meticulously wiped out all their units in battle. Oh_well.jpg. He runs away and I can't chase him down. Aetolian League declares war on me, so I go back to Pella and wipe them out. Byzantine King hired a bunch of mercenaries and besieges my capital while my garrison outnumbers them and my ing 20 stack army is present. All my buildings are damaged and thus disabled, I lose ALL my gold, go bankrupt, have a famine, and waste a turn chasing this retarded AI down. Luckily I can enslave them so I can repair the buildings, but jesus ing christ was that annoying. Not fun at all.

Meanwhile, Pergamon is doing the same to my captured Byzantium.

Also, the enemy AI in battles is god awful. They try to match your formation only to scramble and go when you're about to charge. So you automatically win the fight, but they also camp the edge of the map, so they immediately get to flee and annoying on the campaign map.

[Enosu]

Oh, apparently they also damaged my estate that was being upgraded, but due to a bug, I can't repair or continue the building upgrade, so I guess I lose this campaign.