I don't think Alan Robson is too Geordie at all. I'd say Jimmy Nail or Gazza would be too Geordie though. Although the accent is there with Alan, it's certainly never stopped him on the Radio. How long has Night Owls been going now?? Oh and I'm pretty certain he used to announce at St James Park too.
Out of interest, can many remember the Geordie 'Stand clear of the doors please' announcement on the Metro?