If someone was actually trying to troll by changing their username, then we would ban them. That would apply no matter who they were impersonating, be they a mod or not. Perhaps that deserves a mention in the rules list, but I'm more than happy to enforce it either way, because it's common sense not to troll people if you don't want a ban. In this case, though, I don't think anybody was trying to mislead you.
As others mentioned before me, it's already impossible to have exactly the same username as somebody else, so you can tell the names apart if you're looking closely. Pokemaster has already banned some of the common impersonation tactics (like using blank characters) in the username change threads. Hopefully, in the future we can have a better name change system that staff have more control over.
For clarity, though: if it's going to get people writing meta threads about how they're being confused, I'd rather you guys didn't do this sort of thing, even if you're not serious about it.