Its not an unfair comparison tbh, think about it.
It doesnt matter if Supermans F2 is 8f, or 12f, it will still have the reach, and will still be 0 on block if you confirm it into breath. No character can outreach him STILL, so it basically means that he has to respect a few more options from other characters. At the same time this will give him more whiff punish opporunities if the superman player makes the right read, it wont really be that big of a deal.
Also, it has nothing to do with having a low starter or not. WW is + on everything because her normals are nearly twice as slow as everybody else.
Overall though, IDC if he gets nerfed or not, I think he's alright as he is, but I also know that his metagame doesnt change much, even with around 4 extra frames start up on F23.