Yikes! Thats a lot of RFI!
Youve cited a lot of examples where there is multiple loadings on a frequency without a distance spread but you didn't say if they were sanctioned or not. I must assume they were because we both know there is a lot of "just buy the gear and pick a frequency to come up on. If it interferes, move. And no one bothers to check if they ever had a license to begin with kinda stuff going on.
So assuming the examples you cited are all licensed assignments, did the sharing parties have an understanding from the onset? Were mistakes in assignments discovered? Did any of the "last on, first off" rule play a part in corrective action? What corrective action, if any, was taken?
I know the yahoo who coordinated our frequency submitted it to the FCC incorrectly which allowed AMR in Worcester, Ma. to come up slightly off our center freq and destroy our noise floor. It took a consultant and a week of study to determine how to correct it. And it was all on our dime. All because the frequency was not recorded correctly in the license application. Geeze. Thanks for your valued input, I found it interesting. Not suprising, but very interesting.