I am still planning on putting together a faction profile but I am too busy at the moment.
There is nothing in Legends that contradicts and much that directly, or indirectly support such an alliance. Zero Command is the only one mentioned by name. I would argue that since Zero Command was only mentioned by name it probably was the most prominent and the other warlords mentioned are just small fry like Moff Foga Brill or nonentities like Grand Moff Gann.
If you want to argue that Hethrir was working with Greater Maldrood or Delvardus then provide evidence for it.
Hethrir forged an alliance with Harrsk and then Harrsk died. That does not contradict that fact that there was an alliance.
Let's take the logic you use here and apply it to the Pentastar Alignment of Powers.
The PA was formed in 4 ABY.
Jerec was part of the PA and died 5 ABY.
Grand Moff Kaine died 11 ABY and the PA was annexed by the Imperial Remnant in 12 ABY.
Jerec was only a member of the PA for about a single year, possibly less before he died. Under your logic, since Jerec and his dark Jedi died years before Kaine and the end of the PA, they should not be included as heroes for the PA.
That Harrsk was only briefly associated with Hethrir I am not disputing. I am only asserting that he was briefly but definitely associated with Hethrir. Much in the same was that Jerec was only briefly but definitely associated with the PA.
In my original post I already stated "No mention has been made of Tavion's cult being associated with Hethrir after Desann's defeat but the forces at her disposal lead me to suspect she had the backing of Hethrir- that massive fortress of Taspir III seems like it would be beyond the reach of a lowly failed apprentice to a dark side adept."
I already acknowledged there is nothing that states Tavion was working directly Hethrir at the time. But the fact remains that the bulk of her dark side force users were directly recruited from Hethrir's surviving reborn.
Here's how I suspect it went down: After Desann died Tavion was given his position within the Empire Reborn by Hethrir. All of the surviving Reborn would serve under her and she would serve Hethrir. When Hethrir died she already had the loyalty of the Reborn and struck out on her own.
I also find some similarities between Tavion's scheme and Hethrir's in the Crystal Star. Keep in mind that in the Crystal Star Hethrir's plan was to make sacrifices to Warru so the alien creature would bestow even greater dark side powers to Hethrir. Tavion took the Scepter of Ragnos and drained locations of their Force energy to resurrect Marka Ragnos.
This is all speculation but it is interesting to consider that maybe Tavion's plan was actually Hethrir's. If Warru wouldn't give Hethrir what he wanted, maybe Plan B was to resurrect Marka Ragnos and have him instruct him further in the dark side.
I find it amusing to think that Hethrir would have trusted an interdimensional vampiric slime being more than an ancient Sith Lord.
In game terms, I think it might be fun if Hethrir's faction were to capture Korriban they could recruit Marka Ragnos as a hero. Like how Greater Maldrood can recruit Moff Getelles and Admiral Larm upon capturing Antemeridian sector
Wow there simmer down a mite Manka cat, touched a nerve.
I'm saying that Hethrir wasn't actually part of Zero Command- unlike Jerec and Kaine who were part of the PA, so you kinda shot yourself in the foot with that technicality. We also know that Hethrir had ties to more than just Harrsk because it's stated both on wookie that he helped fund renegade Imperials and sought resources very indirectly from the DEEP CORE WARLORDS. This implies multiple alliances and agreements, not just with Harrsk. We know that Hethrir really only made a solid deal with Fyyar who by all accounts was part of the Imperial Remnant-after Harrsk and Zero Command were already gone- we know that Roganda Ismaren and her son Irek tried to forge and alliance with Harrsk and that they later fled to Zero Command for shelter before hiding on Coruscant with Cronus(before THAT went WAAAAY South) The point is it's a very long stretch for Hethrir to be a hero for ZC since their very tenuous connection was not exclusive by location or association, Roganda and Irek could be though-they were directly associated-not loosely and indirectly.
Also as to the Empire Reborn, they lost nearly all influence when Fyyar and Desann were killed, Hethrir was eaten by magic interdimensional blob thing shortly after and after that the tattered remnants of the Reborn were gathered up by Tavion who had backing from a very small(likely single) Imperial Commander years after both Harrsk and Hethrir had both gone the way of the Dodo. My point is that the Empire Reborn was not part of Zero Command-it was it's own entity, you can make arguments for the Antimeridian, Sy, Lott and Gendarr on proximity and communication while not having any evidence that they weren't in at least communication with the Maldrood due to the locations.
The problem with Zero Command is that in addition to being yet another Warlord faction, they wouldn't bring anything new to the table, they didn't really expand or do anything of note(even less than the PA in terms of lore until Darksaber), we have virtually no information on what they did or who was associated with them until roughly era 4(which was around the Reunification timeline) So for most of era 1, 2 and 3 we have a hero roster that is basically Harrsk. In era 4 you get Harrsk, Daala, Irek, Roganda and maybe Kratas, but then you have a timer til Daala kills Harrsk and you become the IR. You could introduce the remnants of Grand Admiral Batch's command that murdered him and defected to Harrsk but we have no names and they didn't have any remnants of the TIE Phantoms- so that's just maybe some Star Destroyers. Maybe add in Grand Admiral Batch for Zero Command- but he was murdered by his crew who went to join Harrsk-so he probably wasn't keen on the idea. You could stretch things and add in the Empire Reborn but that is still era 4 and gives you 2 Dark Jedi heroes and nothing really new to the game-save maybe the Planetoids Hethrir owned and Shadow troopers(basically weaker generic dark jedi) which again doesn't fix the first 3 eras of it just being Harrsk(and part of era 1 no Harrsk since he's tied to the Empire early on) Tavion was never associated with Zero Command as by the time Desann was making his bid Harrsk was already gassed, so the Disciples of Ragnos would be a split off from the Imperial Remnant, rather than Zero Command.
Look I feel ya on this man, I am extremely passionate about the Warlords and have argued for more of them included but most of them like Zero Command either burned out fast or there is just nothing on what they did. Zero Command works as a splinter faction of the Warlords AI but would be exceedingly difficult to implement as a Player faction for the sheer fact there's just nothing there until era 4 at which point they have about 3/4 of a year until Tsoss beacon- reunification event.
you'd basically have this as a possible era 1 hero roster
Harrsk in Shockwave
Maybe Grand Admiral Martio Batch in ISD Meniscus(stretching)
(era 2,3 same)
Era 4( Irek, Roganda(Dark Jedi), Drost Elegrin(Economy), Garonnin(Economy) Nasdra Magrody(Tech, build speed bonus) Hethrir, Desann, tavion(Dark Jedi stretch) Daala(gorgon) and Kratas(Shockwave?) Harrsk(Whirlwind)
Era 5 Tavion?
That's the trouble.