-- A warning is given, in detail, before joining a GC that you can not change afterwards.
-- The GC quest line even goes through the trouble of making you see all 3 GCs forcing you to have an informed opinion of which to choose
-- You can peruse online the list of items available for sale at each GC (in case that sways you)
-- You can peruse online the list of quests/stories available for each GC (in case that sways you)
-- You can see a note from Yoshi saying to choose one you like, not one because of the items/etc. And that you can not change.


There have been oodles of opportunities to choose appropriately.

At the end of the day, aside from storyline, there is no significant downside of any of the GCs. (You are not going to be missing out)

(I think this is the only possible choice one can make that has any effect in game, that one can not go back on).

I think at this point, we have to take 'Personal Responsibility' in having made the choice.