Brown has a 3 inch height advantage & a 6 inch reach advantage. However, if he's attempting to stuff Alves up against the fence than that advantage is nullified. We've seen superior strikers makeup for those genetic disadvantages all the time (Nelson & Hunt immediately come to mind).
Brown hasn't beaten anyone in Pitbull's league. In addition to Hughes & Kos, Alves also has wins over Karo Parisyan (who was quite good at the time) & Chris Lytle (who defeated Brown quite easily).