It's fine; I can see how you'd get the impression since I still am the only one who's actually done it, but it's really something anyone's allowed to do as long as that four-character requirement is met. (And note that it's characters, not players, and the runner's characters count. >> It's an IC requirement.)

Out of curiosity and for future planning, when would be good for you? I'd like to aim the Emperor Rat finale for maximum badasses joining in.