Just tested it, it's ridiculous. Even the idea itself is fail. Doing that will just
buff the high maneuver horses even more. And we obviously don't need that. I lanced someone, he blocked and had the time to counterattack
Instead of trying to "fix" cavalry in some weird ways, try to "fix" what weapons are anti cav. With the current footmen agi and weapons / cav lance angle and maneuver, nearly half the melee players are indeed anticav, either with a pike or spear (normal) or a 2h sword (seriously wtf...).
The only way to nerf cav properly would be buffing people brains, and I don't see that happening.
Also, a very slight buff to couched lances is needed. I think it's supposed to oneshot anyone, and it doesn't.