It depends on how the other folks act. If they are intent on trying to work birds that are over you, then all bets are off. Otherwise, it ought to be obvious what' within 'working' range and what's not.
If your blind is 500 yds apart, then generally I would think if you can't turn a group before they rech the 250yd mark, they aren't gonna work you anyway.....let'em go a hope somebody else kills'em for being so stubborn.
Tom Wiley and I were trying to get to the same spot one morning. Trouble was, we weren't hunting together. Anne and I got there, first. Tom and his partner that day came-in a little later. When they past by us, we heard one of'em say, "They're right where we wanted to be". They knew it was us (cause of our vehicle) and since we know each other and get along well, they knew it wouldn't mess us up if they went-on down the slough about 200yds. When ducks worked them, I shut-up and when they were lookin' at us, he left'em alone until I either killed'em or lost'em. I remember one duck that looked at us and started over toward Tom and Barry. It was about 75yds and stroking toward them. I started to just let'er go.......but in the spirit of friendly competition, I gave her one more try and the duck turned and came-back just as they started to pick her up and start working her. They put their calls down and never hit a lick.
Later-on in the morning we heard some honkers coming down the slough. I couldn't see'm but it sounded like they might peel and miss us both, so I pulled the honker call out and tried to help Tom and Barry get'em back on-line so one of us might have a chance at'em. After I was convinced they were coming again, I heard the honkers were on a better line to Tom and Barry than they were to us, so I shut-up. They kept calling and got'em to fly right over them and they got one of the birds.
You just gotta know what's within your limits (and in some cases, ability) and respect that of your fellow hunters....especially the ones you know pretty well. And be willing to give each other the benefit of doubt when things could go either way.
Both of us had good hunts that morning, and it was because there just
were enough birds to keep it from being such a cut-throat situation. It helps when there is mutual respect between the parties involved and consideration for 'space'. That was the area the birds were working at the time, and there was room-enough to 2 set-ups if eveybody played it right.
Now, the day the jerk (not T.W.) came through our decoys and set-up 60 yds from us?......he got a calling clinic. Anne and I called everything over the hole into our decoys (despite the guy trying to steal'em on the last pass), and killed a 2-man limit of gads, teal and mallards. The only bird the guy got a shot at was out of the last group we shot into to finish-out......one duck flew over him and he had to shove his dog outa the boat to go get it. Dog took it to the bank and ate it.
The next day, the guy told me I wasn't very sportsman-like
.......that I called all his birds off him and his companions
.......I told him the best way to avoid that from happening again was to make sure he stayed at LEAST 200yds from me. I further went-on to tell him (with several young hunters / on-lookers standing close-by) that, if I ever heard of him setting-up that close to any one of these young fellows, I'd wait until he left the ramp, follow him to where he was going that day, give him the allowable 200yds.....and STILL call all his ducks off him. 'Told him, I didn't know where he was from, but that down here, we don't set-up on top of someone else.
So, with the two instances above, you can see that there are differeent ways to deal with 'situations'...........
But the best way to keep someone from setting-up too close? .........earn their respect. As in the case with "Mr.Sportsman' (as we have affectionately 'dubbed' him)
........he'll never 'get-it'.....but he hasn't set-up close to me recently, either.
