It's just obedience training to get the slaves familiar with life in the police state, similar to TSA putting their filthy gloved hands inside the pants of our kids at checkpoints, or warrantless wiretapping, or the private Federal Reserve telling us we owe them trillions to bail out foreign banks. Just training us to be good little slaves and remind us who owns who.
Haskell is in between Tulsa and Braggs. The Camp Gruber Training Site is in Braggs and that's where the Tulsa UH60 pilots go do their NOE training, dust landing practice, etc. Haskell is simply on the way. They might even stop at the Haskell airport to traffic pattern work.
Glock Pride, if the Hawks are flying low over your home and waking you or your family, or disturbing you, you can call the Army National Guard facility at the Tulsa airport and ask them if they could fly over a bit higher so they don't rattle your home, or change their route a bit. The philosophy of Aviation in the Oklahoma National Guard is to fly friendly. We are your neighbors, co-workers, and fellow Oklahomans. We like to be neighborly.