That should be changed.
Why? I have recruited a unit of trained cavalry. Why should my personal skill dictate how effective they are? I believe there is a small modifier to account for your own part in the battle but surly you don't suggest that a unit of highly skilled cavalry suddenly lose their skills when lead by a wet behind the ears noble?
The other factor that is while there are some correlation, jousting as performed in tournaments is fairly different to the standard cavalry charge with lances lowered.
