I agree, but I think a rivalry like Eijiro and Tetsutetsu in the anime can make things even more interesting. Though if you're not really looking for something like that, would you allow them to change their character's quirks to something else?
You make a point I have not thought about, but in the case of allowance. Everyone is allowed to apply until all slots are filled. Also, me and Drew agreed to jump the classroom size from eight to
ten, so eight characters will now be needed. So we will have to see how many applications we have as slots begin to get filled, I suppose. I'll discuss the concept of allowing both presuming we find both applications agreeable to Drew.
Edit: Updated ongoing applications and extensions in the 'characters' tab.