The Tax Rate is how much taxes the peasants pay. Adjusting it, you can raise or lower the total gold your region produces, at the risk of making the peasants unhappy.
The Lords Share is how much of the tax collected the knights have to pass on to you. The peasants don't care who takes their gold, and changing this value doesn't change how much gold is collected in the region, only who gets to keep it.
Suppose that I am a knight. Is my income different if I have a 25% estate with no lord's share, rather than a 50% estate with a 50% lord's share? Does it affect the income of my liege?
In other words, if I'm a lord, and I want this vassal of mine to have 25% of my region's total tax income, does it matter whether I give him a 25% estate and set the lord's share to 0, or give him a 50% estate and set the lord's share to 50%?
