(16 Jan 2022, 1:18 pm)L469 YVK wrote New vehicles for the X93 would allow Volvo B9TLs to be cascaded onto the X20.

It doesn't need buses though 7553 - 7556 would be good enough for the X20. The X14 should be ran by single deckers there's no need for Deckers on there. Argubly the X20 doesn't need deckers either, it's dead half the time. They should be multi vehicle like the X7/X8/X9 with some boards (if needed) Decker the rest single.