German Mechanized may have a bug with stugg III early version short barrel

Playing Beta2  3.1.6c and I noticed the German mechanized doc can build early and late version Stug III with short barrel. Upon looking, they cost exactly the same manpower, munitions, fuel, and popcap. Thing is, the late version gets armor skirts, HE round upgrade, which I thought they had anyway, and the heat round, like the early version. The descriptions are the same, but one would imagine the armor skirts do something. Also, the late version gets to use bushes without leveling up to vet 1, while the early version has to vet. The point is, there is no reason to build the early version if you get bushes, armor skirts, more powerful he rounds for the same cost. Am I missing something here or is this a bug?