When you're hunting public, as long as the invaders are safe not sure there's a legitimate complaint that goes beyond we were here first. The best thing is try to take advantage of the situation. A big party will move almost all the birds in the area they cover. Position yourself to take advantage of that if possible. One time five of us were taking a line down a half of CRP walk-in. Two random pickups pulled up adjacently and three hunters emerged and joined our line, just like that, no conversation. I moved my group over to make room. They had a good dog. They were safe and silent. The other two in their group drove to the end of the walk-in and blocked. All in all, they improved the hunt. Weird but OK.