IMO the military being OP by the DM was intended and not a flaw writing:

A lot of shows like to show metaphorical aspects about real life and politics, stranger things does a lot of that in its own way.

I think the soldiers in the military that were given their regular weapons to fight off something greater than them shows the perfect reflection in real life. Dr Kay doesn’t need protection just bait, the only protection she needs is what she knows and who she tells, we know she doesn’t tell sacred information to her employees,, she needed money, money for her to make something to protect everyone from vecna except she does it for power, leaving the military for nothing, using them for time, and bait.

one soldier already spoke against this and was obviously shut down.