With Cliffrunner Behemoth your not about to run it in a deck that contains a zombie outlander as its not worth splashing a U/B/G isn't a deck. Its certainly best in naya but yes its worth running in a deck with either of its ally colors. Your Pick on the other hand is both of its enemy colors and thus they are VERY unlikely to be run in the same deck.

Taking Sighted caste-sorcerer, Rhox Meditant or even Corpse Connoisseur leave you a lot more open to playing your first pick. Simply put there is no reason to give up such a potentially powerful card for a random Outlander you have no reason to believe your going to play at that point.