What's with the troll thing getting brought up all the time? I think it's pretty obvious that people are just trying to start up a conversation, even if it's a tongue-in-cheek exchange. All the legitimate theories have been talked to death, so this is just a way of keeping the conversations going until someone comes up with something else.
In regards to the theory I think it illustrates an assumption that could be made about the game if one were to experience only part of it, or to simply look at the characters alone without knowing the story. They made strong ties to Squall and Seifer in an attempt to make them out to be rivals, which could be seen as more than coincidental. Both specializing in gunblade usage? Okay. Both having matching scars? Alright so they have a counterpart thing going on. Both have a sorceress-knight situation. Both are about the same age. Both come from the same orphanage. Both have forgotten their past. Both are unaware of their parents at the beginning of the story. Both went after the same woman. Things are starting to go a little further than parallels. If not for Seifer's blond hair and age advantage over Squall this would be a perfectly reasonable assumption. I would not be surprised if the writers did not consider it at some point, so perhaps the spirit is there. Maybe they just wanted to avoid the cliche.
As long as we're throwing these out there what about Ward Being Seifer's father? No one really knows what he did while he worked as a janitor. He could have left a pregnant girlfriend behind to go help Laguna liberate Esthar, only to find that they were gone when he returned. And since it seems like the Kramers ran the only orphanage in the world, well you get the idea. It could explain why Seifer is so much taller than everyone else, and explain where he might have first come across the sorceress knight movie. Before anyone cries non-sequitur arguments and self reliant fallacies, I assure you that I am in no way convinced by my own words, nor is that the point of such a proposal.