While they do put in a lot of miles, here in this patch we dont have many services operating from as early in the morning till as late as some other parts of the country. Check out the Arriva app's live map sometime, you see nothing up here at 5 AM but loads in Arrivas other divisions, and the same late evenings too.

So I dont think the buses get as flogged to death as people might think, any issues are more likely down to the desire to buy as cheap and lightweight vehicles as possible.

I'm not knowledgeable about all the different types out there, but would whatever buses Coastliner use for their services not be a good idea for Arriva on the X15/X18/X93's? They have similarly long routes. But even then they replace and cascade their buses after a few years.