Lots of undergrads from Wharton Finance, Stanford Computer Science, Harvard AppliedMath, etc (finishing undergrad summa/magna in 2 or 3 yrs, not 4); then 1-2 yrs as financial analyst at GS/MS/CS; then directly promoted to associate and beyond
By mid-'90s at Wharton, many upper level finance courses would have an easier grading curve for the MBA graduates who couldn't otherwise survive vs the sharpest undergrads
Today, an MBA from anywhere merely distinguishes one as a retard who either went to a crappy undergrad and/or couldn't figure out how to be paid and promoted in the Darwinian world of HF/IB/PE...