I'll keep this short and simple.
How about a feature where we can add iron man to the group at a later time?
for example: me and a friend already made our GIM and another friend wants to join in at a later time? you can't at this point in time.. no sir. restart!
but what if we could add that person? directly? all they had to do was just make a new character, which shouldn't be a problem since he's already new!
that'll reduce the nuisance of everyone having to start over. it'll make GIM more interesting to see how it all works out.
ofcourse, as it stands, these people shouldn't be allowed to leave their respective groups either... this isn't a flex free for all ironman joke....