Is this realistic though? I've never seen a region with 50% lord's share and knights who are willing to stay there. It's usually closer to 10-15%.
That's not realistic either. A region with 6 nobles is extremely rare, a region with 1-2 nobles is the norm.
I always put 50% lord's share on my knights. If they don't like it, they can get the f out! I usually award those who dedicate more to the region. Sending them more gold or increase their estate size.
A region with 6 nobles is indeed rare. That is why we are shrinking regions to have more knights per regions.