Interesting idea. At glance at Muni's wiki profile, I'd have assumed he was a closet homosexual as he had no kids despite being married. When you look at Paul Muni and Ché Guevara photos, it's impossible to not see the resemblance.

Thing is, assuming wikipedia dating is correct, there's a thirty-three year difference in their respective ages. By the time Che showed up in Cuba in 1958, Paul Muni was already white haired and entering his sixties. I've no reason to believe that the most recent secret advances in cosmetic surgery and hormone therapy at the time were up to the challenge of aiding a man in his sixties to look half his age. However, it's entirely plausible that Che was actually one of Paul Muni's bastard children by way of an Argentine lover, or the result of artificial insemination using Muni's semen.