I can’t imagine that this is not the sort of conversation that goes on all over the range low-paid employees, particularly where physical strength and resilience is seen as a factor. I have in mind an ‘industrial’ bakery i worked at in the 90’s where men and women worked in different parts of the production chain but paid based on technical complexity or supervising others as opposed to how hot or heavy your work was.
I expect there is something in it for this to have got so far in such a notoriously anti-union employer. Also iirc my sister in law was paid very well in the warehouse side when she worked for them, stacking, sorting, order picking whatever you call kt but hardly in a position of seniority or responsibility: perhaps my s-i-l was not a unique example, and maybe there are already other women doing these jobs and managing fine and getting paid more.
Btw, ‘every little helps’ is the strapline of tesco, non? But that patting your jeans pocket thingy probably sounds less sardonic given the story. OP should be taking comfort in the idea that minimum wage earners in asda are a not inconsiderable part of the welfare bill in the uk via tax credits and so on, so the more they get paid the less his taxes supplement their wages (and asda’s profits for that matter).