These look exactly like my three BO pullets that are the same age. My girls will spar on occasion as well, I think they're just establishing pecking order. I originally had four but one turned out to be a roo. It was very obvious that he was a boy by the time they were 4-5 weeks old. His comb and waddles were much bigger and much brighter red. By the time they were 7 weeks old he was crowing. I think if you had a roo you would probably know by now.
my australorps didn't crow till around 4 months, these 2 girls were raised with my incubated Cayuga batch and now think they are ducks and have nothing to do with my established flock.