first off... Welcome DonR. you stated "If Fredo were somehow to have control, perhaps Roth could fool him into thinking it was not actually him behind the hit that night."
but DR, that's just it... Fredo didn't need to be convinced that it was NOT Roth. HE KNEW... and not only KNEW... had something to do with it (either directly or indirectly). And maybe his involvement was indirectly, which I have come to accept. In which case, Fredo may decide to go after Frankie, but I don't believe that he could really "out-fight" anyone; considering his dimwitted dameanor (sp)
"From now on, nothing goes down unless I'm involved. No blackjack no dope deals, no nothing. A nickel bag gets sold in the park, I want in. You guys got fat while everybody starved on the street. Now it's my turn." (King of New York)