I think NE Superman could make it competitive if he somehow cut loose faster before KC Superman did based on virtue of feats alone, but KC Superman simply operates on a higher level than him due to his having absorbed more solar energy.
Obviously the mainstream version of Superman (or any character) will have way more feats to fall back on than an alternate reality version of him, but the intent was obviously to show that in a direct comparison, KC Superman was superior.
Hercules busted New Earth supes jaw in one blow. Nearly broke his fist on KC supermans face and KC completely no sold the blow while it sent New Earth Supes flying.