you do this could from city centre to top of Maryhill road,,like saying 240/255 from tollcross to BBS but not from anywhere else.Generally the rule is that Every 20 Minutes or better is a high frequency/core route.
Common sense would dictate that the 60/60A/61 should be branded together with the same vehicles advertising the 5 minute frequency.
First operate services that are InterLinked on a corridor to offer a Super hedway but cant advertise this as this a five minute frequency without the small star and small print.
Hence why the changes to the definition of a high frequency service and the fifteen minute rule