If you think about it... Tunney had a perfect style to trouble Louis. Could he do better than Cann? Could he win?
A fit and prime Louis does what Dempsey did in the second fight but better, more emphatic and the ref could count to 100.
Gene would give Joe some issues but I think Louis would finely calibrate himself on the fly and catch up before round 10. Just imo.
8 out of 10 Louis catches Tunney and it goes downhill from there. The other 2 Tunney does what he did to Dempsey but really working hard to escape and takes a close decision. Tunney was heck of a boxer and very smart could figure out his best approach just that even so Louis was too good.