Well looking at it this way if Arriva don't make changes and keep X21/X22 every 30 mins each after the line opens...

- X21/35 - 8
- X22 - 5
- X14/X15/X18 - 12
- X16 - 2
- X20 - 4

That's a total PVR of 31. So there's 31x E400MMC and 6x B9TL

Could easily allocate 7401-06 (with Euro 6 mods) onto the X16 & X20 with 6x E400MMC going the other way onto the X93. Going even further, the X16 could go single deck and doesn't even need to be run with anything heavy duty, which would again free up a few deckers for either spares or summer X93 extras.

Or going one further given that 7401-06 could be ropey given their uses.......they do easier work such as the Blyth Expresses, 43/44/45, 306/308 with 14/64 plate classic E400 going on the X14/X20