I don't have my eldar codex to hand, but I'm reminded of the following [url=http://www.games-workshop.com/MEDIA_CustomProductCatalog/m3170233a_40K_RULEBOOK_v1.4_APRIL13.pdf]FAQ[/url]:
Q: If a model is listed as possessing a specific Warlord Trait in his Bestiary / Army List entries, do the effects of that Warlord Trait apply if the model is not nominated as your Warlord? (p111)
A: No.
Thus, the mere fact that a warlord trait is listed in a character's special rules does not mean that you benefit from that warlord trait. The character still has to be nominated as your warlord in order to receive the listed warlord trait.