[Gandalf Parker]

There is only this one...

--mapprov X Set number of provinces (default=150)

But you have to do the math yourself.
You could probably script something to take a number (playr) and do a math thing with it. But I put it into a calculator then plug it into the script. Especially since its common that when a person has a strong opinion on the number-per-player they tend to also have a favorite overall map size or a favorite number of players, so the answer doesnt tend to change much

Nothing is Impossible. Its a computer. The term impossible is a technical term meaning it is possible but probably more trouble than its worth.