Well, we know that Squall was a high ranked fighter in Balamb Garden. We also know that Cloud was a low rank SOLDIER. However, it could be possible that being a high rank solider like Sephiroth was many times better than Balamb Gardens highest rank fighter and being a low rank SOLDIER was as equivalent if not better than them. I'll try to give an example of what I am trying to convey. Lets say that there is a high ranked fighter in a basic Karate school (Squall) and we put him with a LOW RANK 5th degree black belt Kung-Fu fighter (Cloud). Which will win? It's kind of obvious who. It could also be vice versa. I think we cannot really say who was overall better because neither games say which fighting style (Balamb or SOLDIER) was better overall.
Also to add on, we are putting Cloud and Zidane (both protagonist and the strongest in their games) against Squall (protagonist) and Seifer (non-protagonist) against eachother. I am just stating that tought as something to keep in mind. I'm not saying Cloud and Zidane are stonger than Squall and Seifer because then I would just be contradicting my theory in the first paragraph.
In my opinion, this is rather irrelevant.........but thats just me. I would be more than happy to be critiqued by my hypothesis
Sephiroth rules the outer world or something like that? lol