The interesting thing about the herd dynamics right now has to do with the history the horses have together, combined with the reintroduction. When Fritz, Joe and Noble were in a herd together before (Scout was not part of that herd), Fritz was the alpha, although not a very pushy one. In the small heard of Joe, Noble and Scout, Joe is the alpha, and Noble is a somewhat aggressive beta. I've often noticed that the beta is more aggressive towards the other horses in the herd than the alpha - it's almost as if the beta is the enforcer. This is certainly true in our mare herd - Lily is the unquestioned alpha, who just has to walk towards another mare for that mare to move quickly away, while Dawn is our very aggressive beta. Anyway, since both Joe and Fritz have been alphas, they still need to figure out who's alpha now. Geldings seem to struggle with this pecking order issue more than mares, who would have figured everything out in about 30 minutes and gone back to eating.
At one point today, Joe and Fritz stood parallel to each other, facing in opposite directions, but about 20 feet apart. They both pawed the ground and screamed, and then walked away in opposite directions - I think they were displaying their power to each other - perhaps the strength of one's bellow helps them figure out who is dominant. This is a little like the mare dominance display that I call the "high kick", where two mares contesting for the top slot will engage in a high kicking contest, but not close enough to each other to actually connect. It looks like a display of power.
Noble was doing his beta thing, occasionally running at Fred and Fritz with his ears pinned, and driving them away. So it's hard to see how the Joe/Fritz/Noble dynamic will shake out in the end. Fred, as before, will probably be subordinate, as will Scout, who's the baby of the herd.