Question!
Which one is better to side with? Lords or the rebels?
Personally I've always sided with the lords but is there any benefit or consequence from siding with the rebels?
Lords is the best path. Elis will have earned the loyalty of their current leaders while also having control of their future leaders whenever they come into being. Since he basically killed off majority of their radical young generation. He also doesn't give the elves too much power and will keep Cass hidden family out there from coming forward as well.
The Rebel path isn't really the best, but it's the second best path out of the 4 possible ones. They're rebels after all. If they did it once. Against their parents no less. They'll do it again as soon as Elis does something they don't like in the future. They'll also teach their children, whether directly or indirectly, that it's okay to do things like that as well. Plus Elis has less control over them because they're secretly being "assisted" by the elves.
The Pacifist route is just the Lord's route with extra steps. Not really worth it since to fully complete it, you basically have to let Catalina die and even then, you don't kill Cassius, if I'm not mistaken. Which kind of makes it all pointless. Yeah, less people die but you only really accomplished killing Henry. This being right before going back on the Lord's path anyway.
Then there's Cass side, if you're on the Green Path. She doesn't give you any choice. She gets her family, the Blackspit(?) to kill both sides as they fight. This is probably the worst path next to the Pacifist route. But for a different reason. Because you're letting a completely unknown faction rule over the West. One that you'll never control at all.
So from my own view. The Lords path is the best path, if you care about having control over the West. You gain the loyalty of their older generation. While also weaken they're younger generation and putting the weaker individuals in power. Individuals that may be loyal to Elis (Lockhart and Valerian). Or if you're like me, putting your secret children in power later (with Elin, Priscilla, Valeria and possibly Josephine). You're also not letting outside forces like the Elves or Blackspit gain power and influence.
That's just how I see it. I'm sure other players have their own reasons for supporting the Rebels or the two other paths. But for me, the Lords path is the only one that'll always be the canon choice for my Elis. The others I would only do on side playthroughs. Like doing the Rebels path so I can have Lockhart hear me fucking his mom, Priscilla.