I have somewhere between 5 and 10 level 2 "walkers". Most made for just a one-shot NPC appearance, but a few are the real-life ID of a super, like "Mary Smith", the secret ID of Impervious Girl.
A couple are actual RP characters like a civilian detective or journalist, with a backstory and personality, for when you just don't want to always play a super. Regular people do wander into Pocket D all the time.
To be honest, though, (even though many of these characters should not have actual super-abilities) any who actually have importance or names I'd need to protect, I could level up to 5 in a few minutes without much trouble.