Crawley also has editorial issues. BBC SE claim it as theirs, most aerials point to Reigate and Crystal Palace with has BBC/ITV London, Meridian cover Crawley Town FC matches, ITV London don't. You can't switch Reigate to BBC SE/ITV Meridian as it's a SFN with Crystal Palace. A nightmare for the M23 corridor which BBC SE covers editorially, yet the majority of viewers with DTT are stuck with the 'wrong' news that has a Londoncentric skew.
Crawley news features a lot on Meridian South too.
Its just cheaper and easier for them to use the same reports region to region, and they can get away with it, as most viewers won't know or care what the official editorial regional boundaries are.