This is an interesting premise, although I'm challenged to wrap my head around the timeline. I've always assumed that the two universes split either before or at the latest when Alt-Martha and Alt-Jonathan died. I may be missing something, and freely admit I'm not up on split universe fiction theory. If the universes split when Alt-Lois was lost in the Congo, wouldn't the universes be identical up until that point? Would the difference in the two Clarks' childhoods need to be explained? I can see Tempus going back, if that's possible, and adjusting Alt-Clark's childhood to suit his own evil plan. I wonder if that would create at least one more universe. Although Tempus might enjoy having multiple universes to play in.
