The run up the ramp siege in vanilla M&B leaves much to be desired, namely only one ramp and if you use battlesize changer it is nigh impossible to win those fights due to the sheer number of troops on the wall.
The only other sieges I have played are in 1066 and the AI pathing when you are outside the city gates is terrible. Granted this is .751 of M&B but I dont think the AI pathing is much better in .808. The in-city fights in 1066 however work rather well and are exhilirating.
Laying siege could have multiple types of fights. The City could decide to ride out and womp you to prevent your siege from blockading revenue/spawning defensive parties (Open battle on map). You could also assault the castle/town but this would require a custom map. If you rule out non-tethered siege equipment(catapault / ballista(seeing as you banned mechanized ranged equipment ;P) and just allow for a battering ram at the gates. Have a ram pre-placed at the gates and if there are more than 6 troops then it starts a bash animation that ticks down the strength of the door til 0% and door is open(no clue on if this is remotely possible). Problem with this is that the AI pathing is quite bad and the ram will act as an impediment to your rushing forces once the door is breached. Alternatively you could simply auto-calc the death of some of your army that leads up to you rushing into the gates... pre litter the field with dead soldiers / arrows and you start by facing a wall breeming with angry archers and a bashed gate bristling with spears awaiting your charge. You could use the vanilla siege map.. heck leave the ramp of pointy death there, want to run up... go right ahead!
Otherwise its a great mod, love not having to worry about funds and It is one of the harder mods to play with. I rarely take on more than 2 opponents as even the best armor does not hold up well against the devastating weapons in this game. My favorite loadout is 2 sets of bodkin javelins and a watered steel bastard sword/shield and spirited light charger. The reach and speed of the bastard sword is a huge advantage on horseback when dealing with the hordes of extravagant sabre wielding lunatics on fast horses. I have tried all foot armies, and a horde of Elite infantry holding their backs to the map edge are pretty darn efffective but I enjoy hordes of elited mounted archers over all other units in the game.
One other suggestion if I might. Would be nice to order follow, stay ,patrol here to your forces(like TLD). Would really add to the overland map strategy. Do cities pay for the parties they spawn? Is it possible to economically crush a city by destroying its forces relentlessly before laying siege? Would be nice to know.
Thanks again for a great mod!