I was thinking that you could play as any Major race (huemanz, Greater good Tau's, Bloodthirsty Orks, Cliche Eldar elves, Depressed Teen Dark Eldar) Save the Tyranids due to there RAWR KILL EVRYTHINGish behavior and the necrons due to plot reasons

I was thinking of a plotline that would involve A tiny squad of different races Attempting to put away there differences and join together in order to survive against a attack of Edritch horror Tyranids,

that and I'm obsessed with the Tau.