I think Jimmy takes the decision. He was established over the championship distance and was very well seasoned by the end of his career. I can't see Lyle subjecting him to the kind of sustained punishment Louis needed to wear him down and take him out. Lyle tended to box boxers and slug sluggers. I think this would be more of a chess match, and that would favor Braddock.
Braddock seemingly always gave it a go, even when not at 100%. Lyle had more potential ability, but too often switched off in performances. IMO, Braddock wins six times out of ten.
Agree with what's been written. Just to add that Braddock has the combination of assets - granite chin, spoiler - Lyle would likely find extremely frustrating.