Does it really make sense to have the path of warrior and the path of defender?
I mean... If you are going to develop your hero into a "battle juggernaut", you don't want him to just make a lot of damage or to endure a lot of damage. You want both. So I see those tow branches two branches of the same path.
The skills from the defender that help protecting your army would make more sense in the Commander path, as that the kind of things generals and leaders do.