I don't have either (rogue one variant or a Rex/Chaze/Cassian/DN for most game modes), but my shard has one FO and one resistance squad in top 20. FO must be better on O because usually ranked higher. But resistance is tougher to beat. I probably bat 85% against resistance, and between 98-99.5% against FO. If your objective is arena I'd go resistance from what I've seen. FO is a more tanky/less assisty clone squad in arena IMO.
And if your objective is another game mode, it seems the consensus is resistance. So, resistance is probably more broadly useful in most modes.