I propose we have team #Gothicwars and just run as xenos. Chapters can play as Chapters, then members have to option of going with, say, [GWRS]Space Wolves, or [GWRS]Xenos. Or we set up [GWRS]Eldar, [GWRS]Dark Eldar, [GWRS]Orks (Ha!), [GWRS]Tau, etc.
Just an idea. IDK who'd run what or how it would fly.
Won't work, there are too many people who want to play and act differently. Just look at the chapters on here, for example the DA and NL chapters, the first is "win at all cost" and the second is "it's a game, where's the beer". Those attitudes don't match up well in guilds and it would result in them tearing apart much the way the Dark Angels shed off the Derp Angels.
Multiple guilds leads to annoying politics, but it allows them to function better on the whole.