It seems pretty split on whether to go with STF chars or mains....
Id agree to stay with the mains because honestly this is a tournament for the best of the best and the best tend to be grizzled war veterans of Crpg and thus all will have looms/gens and higher levels. I honestly dont remember Crpg ever being very fair at all, everybody started this game as a peasant and was brutally murdered for about a gen or 2. The only people who may be "disadvantaged" are the players who are at gen 1-4 and lets be honest they probably wont be in this fight because they dont have as much experience as the rest of us entering this competition. I dont see the harm in pitting looms against looms and its not like one individual player will be able to defeat an entire team because he has fully loomed plate armor.
The most effective team is going to be the most experienced and cohesive fighting unit and looms are insignificant in comparison to that. Looms to me only enhance a persons fighting style making it more unique so why dumb that down by forcing everyone to be on STF. The best part of Crpg is that people have a set fighting style depending on their build and looms and that shouldnt be taken away from them.
The only real benefit i see about STF is that i can change my build to anything i want depending on what my team would need instead of being picked for what my main is known for.