ANE have often been lumbered with older stock.
Even though they have invested in new vehicles recently - the biggest batch for a long time (since the 90's Lynx and Delta investment?), there is still the odd influx of older stuff.

Taking a step back, the refurbishment of older vehicles makes some sense.
Take the X20, a new extension (which is totally unproven), but with vehicles given a refurb (on the cheap?) which obviously has the ultimate goal of encouraging growth.
Tying it in with the X15 and X18, will maybe attract tourists in summer months too, if it looks and appears a nicer vehicle than seen currently.

I can't see bosses being able to justify new vehicles for the X20.
If the route takes off, then with the next lot of investment, we may see something newer on the X20 by way of direct purchases or cascades.

I think the X93 can fall into this category too.
A route bothered by all sorts of issues in the past, may be able to continue improving, following the upgrade we have seen from previous.