Jonkster. You write as if you really don’t know what is going on here. I doubt this.
I will say again. It has also been stated by others on this site.
The radio frequency boundaries on the charts do not primarily reflect the range of the ground located transmitter. They are there primarily for other purposes.
If you want the maximum chance of communicating to a ground station go for the one which is closest. That’s why all good GPS units have this function.