You're true with the support they would, however Gabriel.
Outcasts are still BoS just as the EC BoS are, they either made their way back to the west, or continued their mission.
Prime was severely injured not lost forever, and the fact they got him working and gained vast ammounts of resources and tech in the progress.
Is worth several points in the EC BoS' favour.
The Outcasts would not side with CL, just as CL would not side with the Outcasts, especially not over the EC BoS, for obvious reasons in both games.
At best they would remain neutral, at worst they would provoke both sides as a complete independent not a ally of either side.
Outcasts, not saying they would side with CL, but think about it, Outcasts value technology above all else, what does ECBOS do? They blow up Raven Rock, filled with Tech, send Prime, a one of a kind robot to his death and then blow up Crawler, another place filled with tech.
Outcasts might not want to "kill" the entire ECBOS but they sure as hell aren't happy about what they have done.
So I think that they would take the chance to take control over the ECBOS when they had the chance.
But I don't think that raiders are gone at all.
ECBOS has already been there for a long time during FO3 and raiders are still the major population of CW.
Things might have calmed down a little but CW is raiders lands. :mohawk: