That's another option - appeal to the Astartes' sense of honour / duty perhaps, in order to drive them against Chaos. Paint the picture of us as kind eldarly allies... (We probably shouldn't have this discussion where the other 3 factions can see it )
are you only going to play eldar because i plan to play agleast most of the factions but i plan to be a astarte heading after chaos and a eldar assisting the myriad guild
Well, I plan to play as exclusively Eldar as I can, but I'm bound to try out the other factions eventually, just to see what it's like for my opponents