I do hope to eventually see them fully playable in Ascendancy one day as well.
Again, this misses what it actually means to be a faction and why this is something doable in ICW but to the extent that it means anything
is already the case in Ascendancy. It's not even that there's no point, or that the workload isn't worth it; it's that they're already there.
What are the components that make an Imperial Splinter faction worth splitting off in EaW?
Name: If you wanna call a faction 'Greater Maldrood' in EaW, you have to have a faction coded that way.
Starting position: Each faction has its own historical starting position and if you want more than one Imperial group, you have to code more than one Imperial group.
Heroes: They exist
Unit Roster: Few appreciable differences between Remnant and Warlord units.
Tech: Doesn't exist in EaW
What are the components that make a splinter faction worth splitting off in Sins?
Name: AI factions pull from a list of race names. When playing against the Remnant, you already ARE playing against Greater Maldrood, Warlord Zsinj, Director Isard, Zero Command, etc. The game even says it.
Starting position: Randomized, and since you can have multiple instances of a race, if you wanted to have historical maps (which we will do some of), you can use multiple instances of the same faction.
Heroes: Not a thing except in flagship mode.
Unit Roster: They're not different in EaW, they would be even less different in Sins. The difference would be switching out the Dark Empire stuff (World Devastator probably for Tector, MTC for the Escort Carrier which the PA already has, and the Galaxy Gun/Sovereign for nothing). Then remove Crimson Command from Remnant and put it in Warlords. The only place there's a significant difference in performance there is Tector for MTC.
Tech: Would, except for maybe 5 techs, be the EXACT same. Same propaganda policies, same focus on military power, same similar diplomatic outlook (kill everyone).
So again, you ALREADY have these groups represented within the Imperial Remnant in Ascendancy. The Remnant is already any Warlord, it's not just the Moff Council or whatever. The only reason to do it differently in EaW are the heroes which don't exist in Sins, the fact that they can be
called that name ingame which they already are in Sins and that you can put multiple instances of them in a different place, which they already do by default in Sins.
The only thing that would make any difference is make a tech ingame which declares loyalty to one group over another and then gives slightly different bonuses and locks out access to some units in favour of others, but again, the only place where this has any appreciable gameplay difference is a trade of World Devastator for Tector, which is not a good trade. The differences would be Crimson Command for the VSDII for Maldrood (upgrade), CR90 instead of Lancer for Zsinj (a cosmetic difference, if it even fit on the build bar, which I think it wouldn't at this point), and access to superweapons/MTC for Dark Empire (and they technically could even have access to the Crimson Command stuff). PRoblem here is, why would anyone ever do anything except Dark Empire? Even this wouldn't change any visual indication of who you're playing as; you'd still be called "Tropicana OJ" (if you're me) and the enemies would still be called Greater Maldrood or Zero Command.
What kinda units are the warlords getting to make them unique from pentasstar/imperial remmant
Very few, no new ones that aren't already NR/IR/PA units (except where someone may get the Providence because why not). They aren't and aren't supposed to be unique roster wise, they're still Imperial splinter groups and the other factions already cover almost every single Imperial unit that isn't associated with a specific person.