Technological progression over time in Star Wars is a funny thing. Its often viewed that the galaxy is caught in a technological plateau with minimal developments occurring. While the tactics were very different the technology employed in the Clone Wars is not to drastically different then what was later used in the Galactic Civil War. Of course technology improved but nominally. This is why seeing ships like the Pelta and the Arquitens and Gozanti fight alongside Nebulon B's and ISD's isnt such a big deal.
However in the thirty years between Return of the Jedi and The Force Awakens its very clear technology has advanced significantly. This makes a ton of sense. The Empire turned First Order has spent thirty years in hiding, licking its wounds, revitalizing its fleet and improving upon the bones of the Empire. Their standard Destroyer is twice as long as an ISD and boasts a larger crew and armament. The turbo lasers employed are considered far superior to the Imperial era's in terms of power and recharge rate. Even the New Republic is building ships such as the Starhawk (yes I know that its a rebellion ship but I imagine thirty years later they're even better) that are more powerful then an ISD.
This upcoming war between the Resistance/New Republic and the First Order is a separate and very different conflict then that of the OT even if there are visual similarities.
Star Wars Armada is in a tricky spot when it comes to material from the sequel trilogy. This game is set in the Galactic Civil War and theme is a very important aspect this. Nothing beats moving a model Star Destroyer and rolling eight dice against a CR-90 corvette or sending swarms of ties and x-wings surge into each other in massive dogfights. The force awakens didnt add a lot of new ships to the universe but I imagine the next two films will. So the question stands what does Armada do once they come to the point they'll want to produce ST era material?
I don't think Armada can get away with how X-Wing solved this quandary by merely merging them into the Empire and Rebellion. The moment that happens the galactic civil war OT theme is kinda shattered and the game becomes a weird amalgamation of all star wars canon. For instance imagine if this game were centered around the Clone Wars, wouldn't it be strange if the Republic was given Tie Fighters and Star Destroyers and the Separatists employed task forces of MC-80s and Assault Frigates. There needs to be some division. This is where I think the New Republic/Resistance and First Order will become the third and fourth factions of the game.
I think that if the New Republic/Resistance and First Order became factions they should be able to retroactively use any ship currently in the game. Meaning I think Armada should do the opposite of X-Wing and rather then try to fit the ST ships into the OT factions, just allow the ST factions to use any of the OT ships. It would be cool to get a CC style box that gave new titles and maybe even ship cards for ST era versions of OT ships.
As another note I think besides theme and feel ST era ships are so powerful compared to their OT cousins that to properly represent that in the game, it would unbalance the meta to simply squeeze them in right now into the current factions.