The reason why the Sturgian bonus is so strong even though it doesn't seem like it would be is because the description doesn't actually match its true function. The way it actually works is that if a Sturgian party is in snow, they get a +20% boost to their base speed. That means the maximum boost they will get is a full +1.0 speed. If it were to work as described, the maximum boost would top out at +0.1. As a comparison, the Battanian bonus gives a max of +0.45 speed, and the Khuzait bonus gives a max of only +0.2 speed.