Possibly Tiger Flowers had the style to beat Mccallum . H e was by all accounts very fast and skilled, also was a southpaw. Lomatta would be tough because of his physicality and non-stop motor. He probably out-works Mccallum. Same with Walker or Greb.
McCallum was very hard to outwork. Look at Watson, and even far past his prime and best weight he managed to pick off Hardy when he bored in. He had such good stamina and was so smart and economical.
True, but I don't remember seeing Mccallum fight anyone that would crowd him the way those fighters would. Would Mccallum have the room to operate he's accustomed too ? Plus the pace. McCallum was an excellent fighter no doubt. But those were so hard ,hard men. And the fact of Lomatta giving Ray Robinson pure hell . I wouldn't bet the farm on McCalllum beating those men.