Its no surprise to see them going as such a small fleet. When they first arrived during Covid Deptfords engineers apparently didn't like them (but drivers did).

Whilst I associate the X66 with bendy buses, full size singles would be fine if the frequency was increased at peak times or simply just allocate double decked vehicles on the current frequency.

Also, in days of cost cutting and keeping the accountants happy, I would hazard a guess that the Volvos were considerably more thirsty than the Streetlites before them.