Phasma(L) Arena Team

I run your squad, but instead of 5s, I run RG, and instead of Rey, STHan. Most teams I face, it becomes a race to get the tanks down, that's why I run 2 tanks. I find that I can, with a little RNG help, pop the enemy Rey (there is ALWAYS an enemy Rey) before having to think about RG.

In your case, I would replace 5s and GS as @Kagehonoo has suggested - the only reason I use him is because I am one of a handful of people who don't have a maxed Rey.