While there are a large number of possible teams you can have, there are less that are viable. It's like with Uber battling. You can have every single Pokemon, but you aren't going to, since most of them don't work well.
Plus, it's not like we have to remake the entire team for the person and just add random Pokemon that manage to work well in Hackmons. All we're doing with answering RMTs is improving the original vision of the teambuilder.
And Balanced Hackmons has only a few things banned that Hackmons doesn't have banned. They're not all that different in terms of what you can do. Hell, Deoxys-S is still awesome in that, although for a different reason from Hackmons.