If in fact the A-10's were flying in thier training area, then they do NOT have an altitude requirement. Permissions have already been granted, and there is nothing that you can do about it. HOWEVER, they are NOT allowed to fly directly over a house, and that he can call in and complain about. I will tell you though, this will not do anything, except make you feel better.
People with horse farms and such, are normally posted on "no Fly Zones" and are known to the pilots, normally located on the map in thier Flight Operations building.
In case you are wondering, I am a flight crew member in the military, and deal with this all the time, no fly zones, quiet hours, altitude requirements, and yes even complaints from people.
I think who has the right of way, has already been answered.
I do wish I had 20 acres to fly off of though, I am jealous.
Josh