There is already an 8 that runs along Maryhill Road which is the Lambert based one that runs to/from Balfron and Stirling.
Personally, I would have liked to have seen the Glasgow 8 either renumbered or broken up, as it feels like that it takes three days to get from one area north of the Clyde to the other.
The 44, 62, and 66 were just renumbering for renumbering's sake. The 40 renumbered to the 60 I get that as east of Central Station and Glasgow Cross to Parkhead Cross would have been three consecutive numbers had the 62 did not get renumbered (60/61/62).