This makes a lot of sense. Sacrificing a percent of profit from other funds won't make that much of a different in the minds of possible investors, but managing a fantastically high fund must be a good advertisement.
No, the medallion fund existed for 20 years before these other funds were opened.
Was Medallion fund Rentec's only business, or was there other business they could skim from?
James Simons had a funds for tech startups. But it wasn't nearly large enough to support the kind of profits that happened.