[thejeff]

Granted, that adds more complexity to optimizing pretender design, but there is still merit in ruling out particularly bad choices.
(Some of which is already done, right? I don't see cold 3 Abyssia very often. A race's temperature preference is taken into account. Why not preferences for other scales?)

Or are you saying there's less complexity? One set of scales that is optimal for all nations in a large enough game? Even if that were true, (which it is not, there being some obvious exceptions) it wouldn't hold in smaller games.