I had the unique pleasure last night of watching the Timuride horde attack the Mongol horde while beseiging the Mongol held city of Antioch. There is justice in the world!!

Another oddity - a Mongol unit on jihad for Constantinople stands outside the city for six turns without laying seige to the Byzantines. The turn after I take the city from the Byzantines, they attack!!

Otherwise, get your cites up to hugh size with cannon towers - and once they lay seige - sally out - well actually, you don't even have to leave the city for your cannon towers to level the playing field. Normally, I set out pavise CBs (non-skirmish mode), supported by infantry, along with my artillery to just outside the gate. The CB's take out the Mongol horse archers when they attack, the infantry counteratttack the lancers when they attack the CBs, and the artillery just adds to the cannon tower's death toll. When the Mongol foot archers come forward attack them with your cavalry. I used this same tactic successfully with just ballista towers last night - but because of the limited range, you need to sally out as described above to get them in range. In either case, even if you don't drive them off, they won't have enough men left to effect a successful assault the next turn

If you DO want to fight the Mongols in the field - 16 mounted crossbow units, split into four groups each having a supporting heavy cavalry unit. The trick is to seperate a single Mongol stack from the horde. You can usually do this by placing your stack to just within extreme movement range of the nearest Mongol stack The nearest unit will attack but his buddies won't be able to get in the fight. If you DO wind up facing two stacks - withdraw from the battle, since they have already moved as far as they can to contact you, they won't be able to reach you at your withdrawn (campaign map) location.