So little is known about them- one of the problems is how reticent and secretive the Sith were, and they rarely kept worthwhile records (with one notable exception of course). The best way to find evidence of Sith activity is to find evidence of the peoples they affected, but all this happened so long ago and so far away (cue Star Wars theme) that the whole area is virtually a dark age historically. Daemora's account is one of the very few to come from that particular era.
But from what can be established, there was nothing endemically different about those factions, no. Feudalism would imply an ultimate authority, eve if only in name, which they did not seem to have- Daemora described it all almost as tribal, with cultural groups trying to push each other out of territories, sometimes causing other groups to therefore be driven into new areas which they pushed others out with etc. Asall sthis stuff was unfolding over centuries or more, it could be seen in an ethnic sense like this. But as already noted, these days we would less see it in terms of tribes, more a group of people withouut necessarily any racial connection dominated by a Sith Lord. The Lords would typically choose their own successor, or a successor would be 'arranged' for tem by a subordinate, and so the continuity of a faction would go on. Still, it is all only guesswork.
Daemora told many stories about the war. But one story in particular talks about fight to take the planet Acanthus. The Acanthans were allied to the Metephians, and had turned their world into a giant fortress to resist the Kasmanae. In which respect they did rather well; the Kasmanae attacked the world for seven years without success.