Anyone else find it a little silly that the Deathwatch Army is Allies of Convenience with Eldar, and Desparate Allies with Tau and Dark Eldar? ... This may not be true; just going off what I read on 1D4chan.

It's like if Grey Knights were Allies of Convenience with Chaos... (wait had to check that it wasn't true)

Can anyone conceive of a reason why this would ever happen?