Idk. It's like riding a bike with training wheels then taking them off.Lex would get his ass kicked
IDC how much he's trained, superman has SOME experience fighting with no powers and fights for his life on the regular
Superman had all those powers that made it easy for him to whoop people ass. Without the powers its gonna be different. He gonna feel them punches he couldn't feel before. He won't move as fast. He will actually have to strategize and work in a fight