I really dont see this regional split as anything of a problem, certainly not when it comes to the Highlands and Industrial lowlands/central belt. Such minor regional differences occur in every country. If Protestant Lowlanders and Catholic Lowlanders can get on(and they do for the most part) then anyone in Scotland can.
They get along,by and large, in the UK.
At a Rangers/Celtic match? Not so much.
Without English wankers to blame they will fight each other.