corlinjewell

Actually, pg 403 of the BRB says that all three of these organizations hold permanent seats, just saying .

Hey man, just an idea, but if you want them to be not of Imperial origin, then you could make them operate outside Imperial jurisdiction (obviously this creates its own problems like supply, but just a thought). Maybe they go around avoiding other chapters and the Inquisition, offering their aid to Imperial worlds, but being forced to bug out if other Chapter/Imperial organizations appear. Maybe their recruiting worlds are unknown to the Imperium. Maybe the Inquisition is after them, and actually ends up declaring those who receive their aid to be heretics or in league with Chaos (therefore they try to help, but end up harming). Maybe too, you can hint at their multiple geneseed slowly breaking down and leading them to Chaos (very slowly as I understand you want them to basically be loyalists). The reason for the eventual fall to Chaos is that GW basically says all non-loyalist Space Marines eventually end up as Chaos Space Marines. Just potential ideas to get around some of the issues others have brought up (I won't be mad if none of them appear ).

After a more careful read, I think you could name the chapter with what the clans called themselves, "Trueborn". This could tie in with mysterious geneseed and you could even leave the real reason up to mystery. However, I would give a detailed reason why the Inquisition and Ad Mech is okay with the lack of tithing (especially if their recruiting worlds are forbidden). I don't see a reason right now how that would fly, but I leave that up to you. Otherwise cool stuff. I look forward to updates

Going with the Battletech theme, you could remove your favorite clan from those amongst those found on your Homeworld and call the Chapter that (my vote is the Smoke Jaguars ).