Chivalric Sergeants are good with a couple of morale upgrades. The fun unit is the Gothic Sergeants, slow and heavy but able to hold a bridge better than pikes. I use them for castle and river defense when I can't get Swiss Armoured Pikes. My favorite bridge defense is Gothic Sergeants at the center of my U, with pike units as the sides, and a couple of serpentines, organ guns, or culverin on the corners. The rest of my units can be most anything, as long as some of them have some ranged ability nobody gets through unless the enemy has brought decent artillery.

mfberg