SMK's were first designed in the 1950s and have thin jackets because, important to tack-driving precision, thin jackets were easier to form with wall thickness symmetry. They just fall apart in game, though.
For hunting, thick and thin are usually reflective of larger game vs. varmint game bullets, with thinner jackets needed for rapid expansion in the latter type where disintegration doesn't matter. However, jacket thickness isn't the only factor. Jackets are not all made from the same materials. Hardness and brittleness of the material affect how appropriate a design is for expansion, not to mention nose design and whether or not the core is bonded to the jacket. It's pretty hard to say whether a bullet is appropriate for hunting based on jacket thickness alone. Your best bet is just to call the maker and ask.