ah i did consider it but im going to tweak the fluff slightly, and say this:
The reason they left firehawks is as stated, as well as the fact they were forcing marine on marine combat - something my men are going to be against. The same with the astral claws deserters. As soon as the war pushed too far (the astral claws raid on salamander ships just for gene-whatsits) they left in disgust at what had first been about politics had deterioration into the greed that the imperium shared that caused the war in the first place.
However, i realise that means my army will fall apart if ever i have to fight another spacey army so have come up with:
Over time, they became outraged they were branded deserters, claiming they never deserted the emperor they swore loyalty too and still fight in the name of. This bitterness has risen in recent years, causing them to be willing to break their oath of no marine on marine combat should a chapter try to stop them. I'm feeling it. It is fun to create a chapter! I'm thinking dark too. My dark eldar army (that needs finishing and i think might have been a phase..) i think looks okay so far! [url]http://www.lounge.belloflostsouls.net/showthread.php?t=16905[/url]