Hard to say really. I see Roy having a very difficult time in Gene's era..over 15 with different rule interpretations that would likely assist Tunney in overcoming the speed disadvantage. Like janitor said Gene would have a multi fight serious to figure out Roy...whilst Roy is pretty much to hardest fighter to figure out ever, Gene knows what he is doing in there and was a very smart and savvy fighter...Not to mention the naturally bigger guy. I do feel Roy would win fairly clearly in this era of the 12 round superfight...By the time Gene was just getting somewhere I feel the final bell wouldnt be to far away. And the powers that be wouldnt give him another shot.
I do believe master boxers Loughran and Tunney who studied every move their opponents made and then their own responses endlessly would have the keys to offset Jones natural skills for the wins. Conn and Jones speed makes an interesting match-up and if Qawi could get close enough,,,lights out. I will give Jones the nod over Evander at LH.
I agree with you on Bob having a punchers chance but Jones best keep on his bike to keep it at just that. Most scribes think as you do for Ezzard at his best beating Jones but I'm in question mode on a Spinks bout. I can't see either tagging the other clearly and their styles couldn't be more different!! I'd like to know others thoughts on that bout.