Had my first few missions of this last night, very enjoyable. Didn't quite know what i was doing and the menu doesn't seem to show allthe keybinds, eg. couldn't find what the heal button was (until near death and it popped up on screen) or how to get ammo to/from people etc.
The game is stunning and the humour is great. Ran out of ammo a few times and this was only on easy so I'm scared for later but enjoyed it all the same.
To give others Ammo you need the resupply backpack stratagem. Otherwise you cant give them any. Instead just call down the resupply during/after a tough wave from the global ones. Preferably with the rest of the team since its a shared one.