I look at the situation like an incoming prisoner: the people who act like they want to be your friend on the first day are the ones trying to make you their female dog.I plan to lay back, keep my abilities under wraps, and wait until I see people at a similar level before I try to join a group, if at all. If you end up in a group where you're the best student, you're wasting your time as a free tutor. If you're the worst student, you're dragging people down and making them hate you. You have to fit in at your own level of understanding and effort.You also have to be sure you don't get stuck in a group full of worthless people, like gossip-mongers or Republicans.
I kinda just want to find one other student; I am not so sure that the big group of 4-5 people will be as beneficial? Not so sure though...
Ah, so you're "that guy". Even if there is a little bit of truth to what you say.
Also, sandbagging is just as bad as bragging about how much you study and how smart you are. I don't know how you plan to "hide your abilities", but whatever it is, it will probably result in you being labled a sandbagger, a gunner, a loaner, or just a jerk.
If someone invites you into a group just be upfront with them about what you will and won't do. Be upfront with what you want to get out of the group.