Could they beat: Fedor Lesnar Stipe Ubereem Jon Jones that beat Gane Could Sullivan and Jeffries get it done? They both had plenty of grappling experience, and Sullivan in particular was a proven bare knuckle fighter.
As hard as it may be to believe, no, boxers from 100+ years ago would not beat modern day HW MMA fighters. They probably wouldnt even beat them at boxing.
They get washed, modern grappling outweighs theirs by a significant amount, perhaps they may have a strong clinch but the moment they get down via any wrestling/trip technique it is wraps.
