Arriva tend to prioritise all of the contracted services, which I guess is because they don't want to be fined for missed trips. In many cases it makes sense, like the 57A and 777 are just hourly anyway, but when it gets to that stage that they are missing so many other trips, it really has an impact.
They should hire in some buses like GNE did earlier this year if things are this bad. Then they can spend time fixing buses which have been off the road for ages like 1497 and 7564.
RE: Arriva Northumbria Vehicle Allocations