I'm not sure if this is a bug or not, but I've noticed that even if I raise a dweller's luck to 10 for all 6 of them in a room, I'm not seeing that much of a difference compared to a room of dwellers with only 1-2 luck. I even equipped Nightwear on all of them just to see if it made a difference but it hasn't. In fact, I notice that rooms with low luck seem to have a greater chance in getting caps when I collect their resource.

I don't have a spreadsheet or anything, but I have 3 fully upgraded 3x3 rooms, with 18 dwellers of 10+ luck and 10+ on other (Str, Agi, En)

Anyone experiencing this as well?