Quote Originally Posted by Caledonian Rhyfelwyr
I just attacked a Spanish city which had a couple of units of Dismounted Feudal Knights, Crossbow Militia, and a General. Meanwhile, I had a full stack army mostly consisting of Italian Spear Militia and Pavise Crossbow Militia. I had 2 Rams, 2 Siege Towers, and 2 sets of ladders.
you could take the city with minimal casualties. Instead of building rams, you should have built 4-5 siege towers and 4-5 ladders and spread them all around the walls. That way you would certainly found undefended parts of the wall, and concentrate your attack there.

Once your forces are on the walls, AI usually falls back to the square. I always have an archers with ladders ready to rush to the walls and shoot them while running to the square. If you captured the gates, you can also rush your cavalry against them.

In the next phase, send your archers (xbows in your case) to attack units on the square to lure them from the square. Since you outnumber the enemy, you can do this from multiple directions.

As already mentioned, avoid fighting on the walls and on the square, especially with militia against knights as they will get slaughtered.

If you must use rams, take at least 3-4, and send them to the gates all at once, not one by one. Some of them will be destroyed, but one will surely reach the gates. Although I consider use of rams against heavily defended gates to be rather foolish