Werner Bischoff only used Rolleiflex TLRs and created some of the best Magnum photos ever (beats HCB in my opinion), No photojournalist but famous Imogen Cunningham tended to use the normal lens for the formats she used from the mid 30's on she mostly used the Rolleiflex.
Fritz Henle mister Rolleiflex used TLRs for most of his career 75 or 80mm lens only.

Did Arbus use different lenses on her Mamiyaflex or did she prefer one focal lenght?

Dominik