Rohan's comment about only Class 1-A being on the top ten roster is, fairly, a bit unrealistic. However, it doesn't make sense to split our characters up into classes 1-A and 1-B, because that would sacrifice a lot of interaction between characters in separate groups.
If class 1-B is included in physical events (such as the aforementioned UA incident), that certainly solves the problem, but… what would the point of such be? If they're grouped together so often, why not just keep them as one class?
A solution would be to introduce a roster consisting of additional NPCs with random names and quirks filling up a few of the top ten's slots. Granted, pretty much everyone has responded to the results already, which would make adding a new one… difficult. Unless of course, the new roster is just posted on here with the knowledge that all future posts will reference it without old ones having to be changed. It's a bit of a continuity shift for anyone not reading the discussion, but it would help fill the glaring plot hole that is all of the top UA contestants being exclusively put into class 1-A.
TL;DR (Why did I type all of this out?) I'm inclined to agree with Rohan on this one. However, it might be a bit late to alter the top ten roster seeing as everyone has posted. Unless Dekiru would like to introduce a kind of informal roster retcon, in which the new top-ten consisting of both class 1-A (player characters) and class 1-B (random NPC) student names. This roster wouldn't have to be edited onto older posts, although the new top ten would be acknowledged in future posts. Really the only thing that would have to be kept solid in a new roster, the way I look at it, would be Tokoyami's placement as number one. As for the other characters, I'd fully be willing to bump Ayato off of the top ten for this accommodation, if everyone else (and Dekiru) is in agreement.