I don't think something like this would be a good mechanic. It punishes you for hitting the enemy.
Thank God, the voice of reason showed up.
If you're tired of seeing agile great lancers, put in a request to have the strength to use the GL upped to keep those dirty STF's with 11 riding from being able to use them. IMO, that's not playing cavalry, that's being lazy. I know a very many people who would be devastated by a change like that. God forbid they learn to play aggressive as cavalry.
I.E. no more being 10 meters away and being able to lower a lance and instagib someone because you have no acceleration wind-up time
or, from a infantry point of view
I.E. Cavalry wearing nothing but rags and riding at the speed of light are no longer a giant threat because they would have to sacrifice some more points from agi towards str to use that dirty GL they abused you with!