It seems like you are trying to make a situation where a knight with 10% and the lord with 20% makes the lord more money than just taking 30% for himself. But this makes no sense if all you do is divide the land.
I do not really know what you are saying here so I can not say if I am trying to do this or not. With this proposal, I am simply trying to ensure that, if estate sizes remain the same, taking on new knights boosts the income of everyone already holding an estate in the region and to encourage lords to have empty estates instead of wildlands. Nothing more and nothing less.
The problem at the moment is that If I am lord of Region X with no knights, I more gold than if I has a knight. The region as a whole will produce more than it did before, but my share as lord just dropped. The only way around this is to tax your knights at 50% and never make your estate smaller.
