Quote Originally Posted by Poor Bloody Infantry
I find the AI is much more willing to attack river crossings than cities, especially with a full stack defending, and for some reason it always does attack one stack at a time a Privateerkev mentioned. If you have at least 4-5 stake-laying archers holding a river crossing against the Mongols is easy, but even without stakes I much prefer defending a bridge to defending a castle.
The only catch is that some Mongol stacks have rocket launchers and trebuchets so you need some trebuchets of your own for counter-battery fire. If you have no artillery, and are attacked by one of these stacks, you need to do something else. Which is, lay stakes at the crossing, but then put your archers on loose formation and along the banks of the river. Also, pull the rest of the army way back so they don't get bombarded. Your longbows' arrows should reach to the other side of the river. Once you cause enough casulties, the AI finally attacks and impales itself on your stakes. You'll lose a lot of archers doing this but it's safer than charging across the crossing yourself into a barrage of arrows, boulders, and rockets.