However, since you can acquire them very early and easily, you could put in the time to develop them. Strength Level Types are comparatively rare, and wolves are one of the easiest you can acquire. Alternatively, if you can get Catalyst on a wolf, you could fuse that to make another unit a Strength Level Type.
The Land Mount ability gives them the option to carry smaller party members, reducing the time needed to traverse a land hex.
They can be sold for 100 gold at Medium size and for 300 gold at Enormous size. Every level above 1 additionally increases their price by 5%.