Eldar value Eldar lives, of any type, over thousands of lives of anything else. Both can switch sides and join the other as seen in Path of the Warrior, or outcast fluff in general. Craftworld Eldar fight primarily to preserve the Eldar race as a whole, putting their deepest hopes in the Exodites. Dark Eldar fight for a similar goal... To preserve themselves. They also still hold Khaine in high regard, and the Craftworld Eldar are the lucky ducks that get to go into battle with him. Corsairs fit so closely with each they could almost be included in either book. (with a link that close its not hard to see how they could ally) Harlies just sit in the middle and mediate all four.
And aren't all Craftworld Eldar Trueborn? I don't recall any of that tube birthing B.S. in their background.
Last edited by Styro-J; 08-01-12 at 07:58 AM.