My pet theory on the First Order is that it’s made up of relatively independent, ehr, not really cells (too independent, though who knows), but branches, made up of the diverse remnants left after RotJ/Jakku. Historically speaking, it would make sense for the diverse Imperial remnants to have spent time apart, then rejoined. There’s a caveat because I can see that regrouping happening three ways; with alliances between different remnants, or with one eating the others. And a third way, mixing both, with a main remnant allying itself to some of the others and blitzing the ones they disagree with. For now, I’m leaning towards third.
If there are various remnants and they’re not that united, it could lead to infighting and one-upmanship, but it could also mean versatility, adaptability.
…Also leaves the door open for moar Imperial remnants, allied to the First Order or not. You know, since we’ll need more baddies at some point.