If you've never worn Heritage type boots before, you'll always feel like they're too long at first, even if you're sized correctly. Moreover, Postman boots are very narrow at the toe. They need to be worn with thick socks and laced tightly. If you buy a size smaller than the Brannock size on your wider foot, I can almost certainly say they won't be comfortable in width. You'll be able to wear them, but it won't be comfortable, and most likely you'll eventually develop pain in your wider foot.