I LOOOOVE fighting cav, the amount of idiots that charge straight into my bayonet, get sent flying off their horse and then gutted like a bitch on the floor is hilarious!
Personally Iv never had a problem fighting Cav 1 or 1, if its a lancer... learn to block down, eventually they get bored and pull out the sabre, and then you give 'em the bayonet.
Failing everything else, just shoot them, need to reload? Thats fine, its done in 3 separate phases, you can get one phase done by the time the cav comes back for another go.
Then. Blow them away. Or the horse. And then gut them on the floor like a bitch. Again.
Against a pair of cav its slightly more harder, but you are more mobile than them, they can hit into eachother, stumble about or hit into the wall you are taking cover against. As soon as the horse rears... stab high and take down the rider, or do the horse over and take down the rider before his clueless mate gets a chance to react.
Cav are easy, people just don't know how to counter them.