...the one faction that makes the most sense of working together with the raiders to defeat an enemy in common is Hades Division since they're human, they should know how much of a threat Shamash is to Earth if he isn't dealt with immediately.
And who's in the HADES DIVISION??? EFFING ANESKAAAA
The first and most poignant thing wrong with this prediction is that the invading factions; Umbra, Hades, Fifth and the Elite Corps. are all human. Yep. Which means based off this logic any of the factions would have as much to gain or lose from helping the Raiders which simply isn't the case.
The Fifth Council, for instance, has long been dogged by rumors of the alleged Sixth Council. If anything the Sixth Council will occupy the Fifth Council's territory. There would really be no better time to strike than after the Fifth Council's Hive computer has been so debilitated and would fit in with how Council insurrections have happened in the past. This pretty much guarantees that Aneska will not be in the Fifth Council and that the Council would gain very little from helping the Raiders during a time of internal turmoil.
The Hades Division invested greatly in the construction of Hecatoncheir and without it they are no match for the prolonged life spans of the Council or the tumultuous hordes of the Wardogs. Aneska was die hard loyal to Krausher and if the Hades Division was in any shape to act then she would definitely be running it and thus would not have time to be a Raider, if they were even in some type of peace.
Which means the Hades Division is not going to be much help to anyone after their calamitous failure. Because Aneska is probably the next Raider the Hades Division will not be in any sort of shape resembling the one under Krausher's brilliant commanding.
The Umbra Wardogs are a strong and hearty group of space pirates and Aleph addicts. The Aleph addiction gives them great personal fortitude to the point that they never consider even wearing body armor. The space pirate in them means they will loot and destroy whatever they can't. Krausher's mech, an amazing Aleph powered suit of armor, would not only be brimming with Aleph but also would have a multitude of heavy weapons caches installed on it, as we know. They would be on that mech the second it hit the ground and they would have stripped it bare and taken anything valuable while burning the rest. One of these valuable things would no doubt be Aneska.
What happens to Aneska after the Wardogs find her probably has to do with recovering her and trying to employ her as a weapon, as they did with HIVE, because they could never simply hire her as they did with Rak and the other mercenaries. She would eventually escape and find refuge with the Raiders as many of the Raiders have done before.
...colleague (Mikah, Lycus Dion & Hans).
Harec tells her of his plans to send the humans back, she agrees...
Harec and the Raiders know that the Legacy is Shamash. There is no returning to Earth for anyone because there is no one left alive who understands how the Aleph engines work. Harec believed that when the Legacy activated it would teleport the humans back to Earth but it didn't. Thus, he cannot rouse anyone to action with such a plan.
Finally, Lycus didn't even know Harec existed until they met after Hanging By A Thread at which point I doubt Lycus would send correspondence to Aneska on the matter. It seems the only Hades people who knew about each other beforehand are Ayana, Lycus and Schneider because even Mikah refers to Lycus in her journal as though they barely knew each other. And Hans was a cook. I really doubt Aneska spent a lot of time befriending the scullery table.