But against team of all gear 9/10, I think she will be manageable. Beatable by other teams on offense, anyway. It just takes awhile to get 3-4 toons to that gear, vs one Rey.
OTOH, it takes longer to farm your own Rey than to get latest gear on 3 or 4 of your toons. So more power to you and all the other peeps who farmed Rey. Enjoy it while it lasts. She won't be invincible for long!
In the meantime, I suggest one possible combo as Phasma and RG with your uber-Rey. Difficult to take down Rey, and once she gets advantage, watch the bodies drop. Oh my. It's glorious. And I'm on the receiving end.
I'm assuming once all toons have end game gear, Rey will go back to being a role-player. The role of being the first toon to die somewhere in round two.