It was a surprise to see the young (two year old) stallion step up and fight a much older brown male today. Because the five year old brown stallion has had much more practice sparring with the other males in his bachelor band, he got the best of the younger male.
But, watching the younger horse go out and start the fight tells me he is (and will be) aggressive as he matures in the future. He is still very young and with his mother's band.
He will be fun to watch as he grows older.