What Happens After Founders Step Aside

The new chief executive of Savage X Fenty isn’t a musician, actress or global fashion icon.

But Hillary Super’s resumé — which includes leadership stints at Guess, American Eagle Outfitters and Anthropologie, where she’s credited with growing the brand’s digital business and launching plus-size fashion — is packed with the sort of less-glamorous skills a young fashion brand needs. (Super was announced as CEO last month; Rihanna…