Seems odd that, of the three frequent services from Mount Florida into the City Centre, the two corridors that have come from far away (the 4 from Newton Mearns/ Eaglesham, the 6 from East Kilbride) both continue cross city towards the University and beyond, whilst the service that has only started within the traditional city boundaries (the 5 from Castlemilk) terminates just a stone's throw after crossing the Clyde, not even getting north of Argyle Street - i.e. the one that's come the shortest distance from the south goes the shortest distance to the north.
I appreciate that there are some long established cross city links (especially to the University or to hospitals) that would be politically hard to entirely scrap but it seems like First are happy having some routes fairly short (e.g. the 5 has a round trip of about eighty minutes) whilst other routes become unreliable due to their length (e.g. the 6 has a round trip of around four and a half hours - so you could do a City - Castlemilk - City hurl on a 5 in around the same time as a 6 would take to get from the city centre just to Clydebank/ East Kilbride without it turning around to head back towards the city centre.
Swapping the 5 and 6 would retain a link from the southside to the University area and from Clydebank/ Anniesland to the Victoria Hospital, with the added bonus of making both services more reliable, since passengers wanting to make a local journey in East Kilbride wouldn't be at the mercy of what traffic was like on the Great Western Road almost two hours ago.