I feel like Jackrum and Polly both do “funny as long as they were useless, and safe as long as they were funny” thing. Jackrum plays up the jolly fat man routine to manipulate people into getting what he wants and discouraging people from further investigation, just as Pols acted like the ditzy bargirl to avoid abomination and convince people let their guard down. I think they both got it instilled in them for similar reasons, being a girl in an overly conservative and militaristic country. They both use it in the regiment when dealing with the higher ups.

This isnt as articulate as I would have liked but whatever.