Looking at more of their local sites, it's definitely left to the local editors who gets direct links on the menu bar and who doesn't and it wont have anything to do with what generates clicks.
Cambs Live has links for both Posh and Cambridge, Bristol does both clubs, Lanc live has 4 clubs linked, yet Oxford Live has no link for OUFC, not does Northants for NTFC, just sports links on those.
Definitely bias at play here, no question about it.