Sanders has the best win and was avoided like the plague by a few heavies in his era, including Lewis. (Who never fought southpaws) He also gave Vitali his toughest fight as per Vitali's own words and nearly had Rahmen out. I actually like him better against more elite competition than Shavers.
Shavers, KO 6, faced much better opposition, and beat more quality fighters, and had more power, than Sanders.... Sanders is probably the most overrated guy on this forum, he was only a part time fighter, poorly conditioned, and usually ran out of gas after only 4 or 5 rounds, and judging by his gut, he looked like he trained more at the local pub than the gym...
Sanders was the better boxer of the two, had quicker hands and probably a better chin. I'd favor him 55/45 here..
I think you're being a tad harsh on Sanders. Earlier in his career, he was in fine shape. Very well-conditioned. His trainer, Harold Volbrecht, may not exactly have been Eddie Futch, but one thing he was good at was getting his guys in great shape. Two other fighters he worked with, Brian Mitchell and Phillip Holliday, were always in excellent shape. Sanders was no exception as a young fighter. He just never had the body type that would ever look particularly muscled or toned, but having seen nearly every one of his fights from the very beginning, I can confidently say that he was in good shape for all of his earlier fights. Somewhere down the line he started to get lazy and started to call the shots as to when he would train or not train. Maybe not getting the fights he wanted demotivated him somewhat, I'm not sure really. I think the Wlad and Vitali fights are the ones most think of when they think of Sanders which is fair enough, but he was pretty much at the tail end of his career and nudging 40. Not really fair on him, I don't think. Anyway, I'd pick him to beat Shavers who punch aside, wasn't all that. Sure, Shavers could do a Nate Tubbs and land a bazooka on Sanders' chin, but the chances are that Sanders gets him out of there first since he's better in several key areas.
Team Tyson wanted no part of Sanders too. In this match up is like Sanders. He's bigger, much faster, and a bit more refined on defense.