Opinions on a 5th for Phasma Team

I'm far from maxed out yet but trying to do my farming early. I've always avoided cookie cutter builds in everything I've done and chose to run on the fun but effective side, so for this I'm avoiding poe and droid teams. Last note to make is I'm f2p. Current strategy is Phasma lead, Daka, Ventress, Kylo Ren, FOST (since I'm f2p and starring a FOTP 3 shards every few days when he shows in the shipments is a ***** and a half). The plan is to get a lot of assists with a lot of stuns from Daka and Ventress and some heavy AoE with Ren and Ventress and a lot of counters with Ren and FoST. So here lies the question. I also thought to myself how hysterical it would be to place a Poggle in the mix, as his damage buff with all those assists and counters would amuse me. My Phasma is 50 shards from 7* so I can farm him easy enough after. But I cant think of who I'd remove. The ST is probably the obvious choice as I know he doesn't get much love, but the very fact that he is FO alone with the double proc chance for an assist works beautifully in my team so far. The next best bet is the sluggish Ventress. I feel she is extremely versatile though. I may also be biased because she is currently my most powerful character, 6* maxed out in gear and level for what my level will allow (58). Thoughts? Opinions? Or should I just leave as is and forget about the pogster