I think that byrocratic diffrences will quickly disappear after the first nukes have hit their targets. For example in Finland you are required to fight as infantry even if you have served in the navy or in the air force. Basic training is same in all branches of FDF. And the same idea is followed in all training. For example naval officer student have to do much feared archipelago warfare course. Idea is quite simple. Enemy is near and little extra infantry training won`t kill you even if you are navy cook.
You have to train your men before you start sending men to naval infantry units or air force field combat units. Germans learned that fact after they send Luftwaffe Field Divisions to Russian Front.
http://en.wikipedia.org/wiki/Luftwaffe_Field_Division