It does seem like the disorder side is thinning out. Here's a suggestion; since the majority of the order side is imperial, why not make it Imperials vs "everyone else" that would allow Tau and Eldar to fil out the "anti-imperial" side (and ican play Eldar and not switch sides). And since the plan is to have multiple tables then factions that shouldnt be fielded together can just be on different tables. They can represent different theaters of imperial expansion.