what it sounds like to me is that the Club wants an exclusive on RC flying in that particular town. You abandoned the original site (probably because the city was going to build on it, a wise decision),another group started using it, and now want all flyers to come to you?
The other group is outside the range of damage, more than the 3 mile minimum the AMA requires between flying sites for Chartered Clubs without frequency sharing agreements. If you want to fly power at that site (with all those electric guys), you have to fit in with them, unless you still have an agreement with the city that you are responsible/in charge.
Sounds like som arrogance is floating around loose at that club...

Roger