Hi Harmon, The cowhide leather is indeed a stronger hide then a lambskin. The lambskin is used mostly for a more casual wear, rather then the everyday rugged wear of a cowhide jacket. While we purchase the heaviest lambskin for our jackets, the weight and thickness of the lamb is less then a cowhide.
Cowhide: 3 oz. 1.2 - 1.4 mm thick, lambskin 2-1/2 oz. 1.0 - 1.2mm. I must assure you that our lambskin jackets do last many years and are very durable. Gail