I think the Scottish output is the weak link. It's certainly the poorest proposition of any station in central Scotland, albeit that it's up against some fairly strong competition.
Problem is, there's a distinct lack of off-peak, off-network slots to try anyone out in. To put it another way, Chris Moyles wasn't ready to take over Radio 1 breakfast from day one, he had to work on his act out of the limelight.
I know where you're coming from, though Kingdom FM, Central and Clyde (networked across the bauer network) are the only stations that produce local output overnight. Folk like Lynne Hoggan & Grant Thomson who despite being great young presenters, still do overnights.
If Scotland becomes independent, surely Ofcom would limit the amount of output network coming from England or would they allow global to syndicate an English brand in Scotland?