I think Shakur’s fight IQ & footwork with the ability to control the distance & get significant punches on target is what separates him.
Tank has more raw Power, but his Defense isn’t as strong, he gives up shots to get better positioning to land that hook & get KO’s. It works against most because he has explosive punching power, but against a smarter fighter that can move the target zone & score on the outside using his jab to keep Tank from getting inside, it might not be as easy.
Shakur landed 123 body shots on Yoshino, obviously Yoshi ain’t nowhere close as good as Tank, but the point is Shakur isn’t just gonna stay stationary & let Tank land power shots on his head, he’ll move, strike & evade, keep Tank at bay & then wear’em down throughout the course of the fight.
Tank is the better power puncher with better hands, but IMO Shakur is the better overall fighter.