He would be comfortable in that company without a doubt. He has that devastating leaping left hook much like Jones.
Yes he did twice in the 1st fight Marshall was 32 ,and 33 in the second, when he spotted Charles5lbs.
I rate Monzon very highly but always think it prudent to have a small dose of healthy doubt concerning him facing fighters like Marshall, Booker, Yarosz, Overlin etc. Guys who mixed frequently in ridiculous depth of competition, won some and lost some, but managed to beat other great fighters on more than one occasion the likes of whom Monzon was never really proven against despite his dominance and efficiency.
On a slight tangent, since Valdez has been brought up does anyone think he has a case for winning the rematch with Monzon? I do, that fight was damned close and I know at least a couple of respectable fight fans who scored the fight for him, albeit narrowly. It seems to be taken for granted on here that Monzon won without dispute but that isn't the case imo.
Because Valdez is a great fighter who would have been a handful for any MW in history. Hes also one of the divisions most underrated Champions and punchers.