Too easy for the attackers, too hard for the defenders.
Siege engines on the defenders side are pretty useless, because battering ram and siege tower need only 30s to reach the gate and walls and then you can't do anything.
In my opinion ladders, siege tower, battering ram - this all should be spawned much further away to actually give chance defenders to use siege engines effectively and have the chance to destroy at least one of those things.
Ladders should be carried and then placed right under the walls.
And of course, garrisons should be bigger and actually we should command those people if there is no one else with higher rank than us.
Anyway, foundations are really good just needs a bit work here and there.
My experience for now: I could conquer 3 Western Empire Castles but had no chance whatsoever to conquer one of their cities, there were just to many defenders.(But I think now that I created more parties in my Kingdom I guess I might be able to take one if there is a war again)
Now the Battanians have almost lost and I want to vulture one of their castles too but I just bounce off.
I try to take the ladders -> Everyone of my men die while I pick out like 10-15 men from my ladder then their archers kill me, too.
I try to build a siege tower -> Half my men die while pushing the siege tower to the wall, the other half die while trying to take the wall (pushing me down from the bridge to the wall while doing so)
The point is: My men die without taking down any Battanians. Their archers have infinite ammunition, the melons somehow attract arrows, at any breach, there are enough defenders that you just cannot push through and every attacker is struck at by several defenders at once.
->Even 200 Defenders are to much when they all shoot infinite arrows at you from the safety of their melons
I'd love to take the defense side of a siege battle, the advantage is so great, I'd probably take on the enemies main army just with my retinue alone. But the only time I actually managed to be at a castle before it was besieged, the enemy actually broke the siege of after a week without attacking. And if you can't read the mind of your enemy and he arrives at the siege first your only option is to sacrifice like 90% of your army to break through, which is not really an option either.
I think besides a ranged damage nerf that should be good across all battles, the individual attacker AI needs to be improved in order to not be so suicidal and pushing physics have to be improved, so attackers can actually gain a foothold on the wall if they jump into the defenders shield first. And joining a defence should only sacrifice like 10% of the current value of troop, or, with good tactics maybe none at all.