I don't think they share the same last, to be honest. They are very, very close though. I think the Grey Southern don't narrow to the waist (instep) of the shoe quite as quickly as the Brawley/Carlson. That said, it's tough to tell by sight alone. FWIW, I think that the current price on Bluefly is good, but that personally I'd spend $50 more to get the Brawley captoes. But if you've already bought the Grey Southern, you are going to be getting a very good shoe to be sure.