What I thought of in the latest round of siege: Hacking doors is boring. So, what about adding a different way to destroy doors. They're all wooden, right? So we can't we SET THEM TO FIRE? If you bring a torch, you can start the fire, steadily removing a bit of hp from it. Several torches means more damage, with all the damage (from fire and hacking) capped at a rate roughly the same as an appropriate number of guys hacking at it. This means:
-no more stupid hacking
-single dedicated players can remove ladders more quickly
-yet chokepoints go down at the same rate.
Oh, and add an extingiush-function from outside the gate, so defenders can stop the destruction if they overpower the attackers.