My clown loaches have an alpha. They follow it wherever it goes although they split as they go for their foods. It had engaged in a battle which lasted for an hour or two. By that time, their black stripes turned palest gray already and they eventually stopped and continued battling again for the following nights. There isn't really any damage except slight graze marks.
As for my Yasuhikotakia modesta, one of them suffered a mild damage on its caudal peduncle. It keeps grazing anyone and despite its injuries, it kept engaging two others to battle. It's not exactly the alpha. I believe it is just second in line as the alpha keeps overwhelming it. My Syncrossus helodes also have an alpha. The alpha just looks perfect in shape and color and is terribly nasty.