It is a separate entity, yes, but being realistic here: given the current level of forum activity, it would not be advisable to attempt to run four games at the same time (three of which would be large) as the increased level of private communication required would affect the activity levels of all three, and that's assuming that the required number of signups can be found in the first place.
Of course there should be games going on at the same time, because SnF is quite slow-paced compared to other mafia-style games, but not too many, that's unfair to the GMs.