I have to admit I've never understood the logic of a mannlicher stock..., extra wood, extra weight, short barrels, nobody puts their hand way out there anyway, do they? ..but they still look cool!
A lot of muzzleloaders had full length stocks so maybe a continuation of tradition. My fascination with them came from long ago when, as a kid, I watched a TV series called "Ramar of the Jungle". I saw my first "stutzen" then and the seed was planted. It was many years before I was able to get one.