But if that big roster doesn't play then you get the rewards.
I dont want to be mean but looking over your gac history, roster and performance, I think you need a little bit of a reality check.
Mods - a lot of mods with no secondary speed including a lot of 6 dots. The resources are already spent on those so dont sell but dont upgrade any more. Eventually move the non speed ones to pilots. For example snips has speed on on the arrow. Also some wrong sets and primaries. For example jka has health sets when he probably wants offense/crit chance/damage. Not a single character is over 300 speed.
Roster - no gls or executor at 6 mil gp is not great. Would stronger recommend going for exec and then SEE or whatever gl is closest. Your last opponent (Drakine) for example has only 600k more gp but has 3 gls and exec. Also, I would stop taking every new character to g7, those are worthless. Farming the shards is fine but any synergistic g12 or higher team could probably hold off every single under g11 character you have.
Gac - yes you had some bad matchups but for example the last round against Morgan you didnt even attempt a single battle so a 0-0 tie that counts as a loss. So why should CG change their matchmaking when you couldnt even send in 1 character to die and get easy crystals AND sunk your rating with a loss? Another big accounts you did beat, and another was a narrow loss. Strategy wise, theres a couple rounds where you either put omi wampa on defense or use on offense in a whole team which invalidates the whole omi. It might be tough with the mods but you used DV lead palp traya vs geos when a good modded DV could solo them. Stuff like that.
In the end you say CG should give you fairer matchups and I agree - you should really be in aurodium where the rosters would be similar quality. If CG seeded all leagues by gp theres no way right now you'd last in bronzium. Good news is its all fixable in time.