I'm lvl 74 and am using Kylo G9, Phasma G9, FOTP 4* G9, Daka G8, and Royal Guard 6* G8. Even at 4* FOTP is still melting people like they were butter, and with Daka and RG subbed it's been a regular stun fest. Aside from both having great stuns on their basic attacks (which frequently proc when they assist), RG has an auto taunt that helps to keep FOTP alive and Daka provides the heals and the occasionally revive should FOTP and/or RG ever get dropped. It's been working out really well for me so far, but I do still have trouble with Chaze teams (due to the lack of dispels), and fast Wiggs teams since Biggs gets full turn meter every time he gets crit (a lot on a FO team with AoEs) and has the potential to one shot FOTP on the opening volley with Comrade-In-Arms (RG won't taunt if they go from above 50% life to dead in a single attack).
I absolutely love playing against Sith teams though. Dooku isn't much of a threat when he's permanently stunned, or one shot by FOTP. I can usually have most of their team stunned at any given time. Sith Trooper is the only one that ever gives me any problems and that's only due to the lack of a dispel.