I don't doubt that some Danes would have the protective instincts as far as guarding. I'm not sure about the "send him down field for a bite" type of training. I really need to try Daisy out, she might surprise! I can also see some Danes being worked to the point where they can be successful with PP work, but it's going to be the exception I think.
I would think that the reasons the military wouldn't use Danes is because they really don't have the stamina like a GSD or similar dogs do. You know how they are- short bursts of activity followed by a nap. I can't see a Dane on patrol all day. The bite targeting part can be trained. A Dane could be trained to bite legs just like any other dog doing protection work. It isn't always the arm that is targeted.
I would think that the reasons the military wouldn't use Danes is because they really don't have the stamina like a GSD or similar dogs do. You know how they are- short bursts of activity followed by a nap. I can't see a Dane on patrol all day. The bite targeting part can be trained. A Dane could be trained to bite legs just like any other dog doing protection work. It isn't always the arm that is targeted.