Siege towers definitely need work. Right now, ladders seem more effective. They should either be ramps instead of ladders or the ai should have enough space and programming to load up on top of the tower before the tower gate opens. When 3 ladders are that close together, the defending ai dogpiles on top of it and will massacre anyone using it. The default ladders are much safer since the ai has to spread between the 3 different points.
That said, so far the best way to break through a siege that I have found is to have everyone follow me, break down the front gate with a ram (the ai very rarely seems able to break these even with full siege weapon set up) and then just run past the guards behind the second gate with all the troops following me. This works because there seems to be two additional problems with siege defender ai:
1) the ai defenders right behind the main gate will just stand there. I don't know if they just don't have enough room to attack or what, but I can regularly run right by/through them and not get hit at all. The ones on the edges will slowly fight back but the ones in the center usually stand there waiting to die.
2) The ai never seems to utilize the kill box between the main gate and the second gate. I don't think I have been killed in there once. It is essentially a safe place for attackers when it should be one of the most dangerous places to be. To be fair, defender ai in general is a problem and one of the hardest parts of being on the defensive side of a siege (half the time my troops won't even get on the catapults or ballista no matter what I click).
The sieges look great and the foundation is there for epic gameplay, but there definitely needs to be some work done here. Maybe custom orders or some different plans that can be given pre-siege to alter behavior away from the field behavior.
Rarely seems do break battering rams? I have had about 90% of them getting oneshotted by onagers every freaking siege, thus making me build them of myself grinding through the idioticly random siege part of destroying the enemy onager only to see them in the assault yet again sometimes! it does seems the best way to minimise losses to have all infantry moshpit the main gate instead of headbutting the weapons waiting for them at the end of ladders and siege towers.
And speaking of onagers or siege weapons in general,using them is such a pain in the ass, since they are so goddamn inaccurate when using them yourself. If I have it finally dialled in as to hit a tower with a enemy siege weapon I literally never going to hit it again no matter what I do, the second shot goes over, the third one I adjust with 1 or 2 ticks lower aim, then it hits almost the base of the tower or somewhere halfway down, so I adjust 2 ticks higher, now it flies over it like I wanna hit the town next over. Its just so goddamn random that I leave it to the ai to hopefully hit something. Also destroying walls is too frustrating to reliable do, build 4 trebuchets, they destroy the onager etc, so far so good, although they are incredible retarded with the random target switching, if that was all and they focus fire on the walls but nooooooo, lets just hit all three randomly and stop at the 1% mark just to hit the other parts before destroying that wall... great. just ****ing great... I want to control what targets to aim for as you should be able to as the man in charge of the siege AND somewhat reliably hit the same spot. I will say 100% accuracy is not needed but the random deviation is just too damn high right now, or is it because my throwing skill is super low, that my aim is ridiculously low, which is also something that should not be linked to siege weapons. If anything crossbow is the better choice imho but we need a dedicated siege weapons skill line of this ****.