Ngannou, Gane is too reckless with his boxing.
Gane would poke at him until Ngannou gets pissed and sleeps him. Ngannou isn't going to just stand at range against a kickboxer(like JDS), definitely not one he knows and has trained with.
2-3 years from now, likely Gane due to aging and wear and tear.
The same thing that happened to Rozenstruik would happen to Gane, they're used to bigger gloves and turn their eyes and heads away from big punches. That stuff doesn't work in mma, unless Gane turns into a wrestler, he'll get clipped when Ngannou puts on the pressure.