I disagree with what RackLuster said,

Don't put a food plot on the border, put it as far from the edge of your property as you can.
We have similar problems and one solution was getting rid of 2 plots ringing the border and moving
them further in. So the deer sightings there have gone down own and they have moved one
bad stand location.

I don't see anything wrong with putting your stand back-to-back with theirs. I doubt it will
start a war that will hurt you since you have 40 and they have hundreds of other acres to bother
with. It also shouldn't hurt you on deer sightings since there is already a stand there, and
even if they don't move the stand, it will probably make them use that stand a lot less, or
think twice about putting another stand on the border.

Edit: Huntingson, same problem here, may have to try that scarecrow tactic.