Distance? Rule-set? Gans would win a decision over the action packed Jack IMO, but would give Gans much trouble with his strength and swarming (possibly like the Elbows McFadden bouts) and would be one of the guys to possibly win. Jack is, unfortunately, a very forgotten fighter. Doesn't help that the footage of him is past it, getting destroyed by Williams. I mean, he has wins over the likes of Armstrong, Angott, Montgomery, Zurita, Zivic and Bratton.
Here is footage of Jack training in the Army, and doing some light sparring as well. This content is protected
I'm picking Gans, I think under his own ruleset it's clear as he spins, clinches and jabs his way to a clear UD. Especially if it's 20 rounds. If not, it's an action packed brawl between a boxer puncher and a swarmer, Gans has issues with this style imo, but at his best the Old Master is good enough to squeak a SD over 15.
