The stereotypical gas-mask-wearing mooks are a little bit ridiculous.
Episode 13 has a few minutes of important developments between characters, and a few seconds of nice scenery.
And in order to pad it out, the writers put in some meaningless gas-mask-clad mooks to lay down covering fire.
And when the long-term plot requires it, they get a radio signal to withdraw, because if they took any meaningful action they would slaughter the main characters.
I feel somewhat embarrassed when I watch stories with such contrived padding.