The problem BigBear, is distance.
Which is exactly why I created the group that I did. The nearest place from where I live that's actually a dedicated lightsaber group was 3 and a half hours ONE WAY North of me, in Ann Harbor, Michigan. Wanna know where the next closest one was? Indianapolis, Indiana. 3 and a half hours SOUTH.
Which is why I created MY group, for people that can't afford to drive that far to spend 2 hours swinging lightsabers around. Are there larger groups? Of course there are. Are there better groups? Probably. How far are you willing to drive JUST to get there though? I'm not willing to spend 7 to 8 hours on the road, just to work out for a couple hours. I can do that at home.
EDIT: and after checking the Link you posted, you realize the facebook group you linked is Closed, right? That means its completely private.
Secondly, and more importantly, Zannah actually lives about 1 hour away. As opposed to the almost 3 hours it would take to attend the Ann Arbor group (assuming nabbing dinner afterwards/lunch before). Distance is once again the factor. The fact that there's a group from "All over Michigan" doesn't really seem to help. She (Assuming your a "she" given your name Zannah!) was looking for a group to MEET, and messaged this one. If she wanted to join a "lager" group, I'm sure she would have been LOOKING for one.