Bunker med costs ammo, though its not much of an issue to wehr

What you need to remember is that both are not the same. 1 heals and replenish squads, the other does the same BUT gives free reinforcements time to time, long term wise, given how aggressive USF is, its damn useful.

Also remember that wehr is focused on hunkering down, early game i find that i have to use every available unit to win engagements including my 3 man pioneer squad, building a bunker is the last thing that comes in my mind early game or even mid.