Actually, both firms don’t really care about the major so much as the elite pedigree(Not limited to HYPSM…but peer elites including some publics needed to be near that level) of undergrad institution attended and having a reasonably high cumulative GPA.
A cousin-in-law who applied to BCG on a lark just to see if she’d get hired as a graduating HYPSM Biological Sciences major ended up turning down admission to several Top 5 Genetics PhD programs when she was surprised to receive an offer from them. She mentioned several times they hired people from a wide variety of majors including Art/Art History, Classics, English Lit, MechE, Chemistry, etc. One doesn’t necessarily need to major in Econ to be hired. She enjoyed her time there and they paid for her to attend a top 3 MBA program on their dime when she finished her 2 year stint.
Also know of several Ivy/peer elite non-economics social science/humanities majors(Poli-sci, History, Anthro, English lit, Sociology) who were hired to work at GS right out of undergrad.