Among the thinner ones goat would be the one with the highest density and the firmest texture.
So you could get away with not having to glue layers.
Depends a bit on the purpose it was finished for.
There's shoe goat and there is clothes goat.
The shoe goat is better for strops cause its thicker.

Lamb is too thin and it stretches endlessly.

Generally the line along the back is the best part for strop purposes.