I would propose slowly ramping it up to 50% over a range of maybe 20 years? Then hold it for 10, and drop it.

From there on it should be fair game. If the imbalance should happen again, then I guess it's just how it is...

(The slow ramp-up is so you don't fill up with the first best women available, which maybe might not necessarily be the best candidates... Which would lead to more bias if they fail the job, instead of the opposite.)

That's their problem. They want to vocalize it, well you can fire them!

Technically they are equal, they just happened to be born somewhere different. So it should be fair, right?

That kid when he grows up might indeed feel weird about all the undeserved money...

Are you serious? How is taking money from one person who never worked for it and giving it to another person who never worked for it going to make one feel self-conscious and sympathetic to the other?

Edit: To directly answer your question, It's not about being sympathetic to the other. They just didn't deserve the money. You "feel" they envy of other people and ask yourself why you and not somebody else. At least if you were the legitimate heir you knew that your family earned it somehow...