there are three group categories that almost everyone is going to be in.
one is a "glitch strategy" like group where you can acess resources on how to play
another would a group representing your neighbourhood, like the "groddle meadow" group
lastly, a group for coordinating core activitives, like the "new streets" group.
there will undoubtedly be competition within each of these categories, but everyone will benefit from being in a group representing each of these three categories.
that leaves four slots.
for maybe two or three groups representing different social circles you are in [think "university of iowa glitchers", "nurses who glitch", "sullivan family glitch group" ] .. but you won't really *need* to be in any of those kinds of groups.
then there will probably be in-game "tribes" that you'll want to join or be recruited into, so groups for a couple of those .. stuff like that. this mess of categories can and should duke it out for members. these will be groups you should probably be joining, but not too many. the limit helps with that.