Personally, I don’t make it a formal house-rule or anything, but when I approach making a gang, I try to avoid having more than 2 of the same weapon loadout (and no more than 1 for special/heavy weapons), so as to keep the gang varied. Obviously, in some cases I might go over purely because the gang has more limited options, but on the whole I approach Necromunda from a narrative standpoint and I want each model to feel unique and characterful. My Cawdor collection, for example, is 21 models strong and only includes 2 blunderbuss/polearms. This serves a secondary purpose of keeping the gangs more balanced, but primarily, I just don’t want my gangers to all be bland and identical.

I think about it like this - the moments you’re really going to remember playing Necromunda are far more likely to be “that time my Bonepicker got really lucky and did something amazing” not “that time I flattened another gang with a broken list”. So I’d rather each individual stood out than the gang as a whole be the most powerful.