(30 Mar 2015, 6:19 pm)Dan wrote Not my area of expertise, I'm afraid!
The "Tyne Tees Xpress" services will remain separate until there's no need for tachos. Arriva North East has recently split most of its EU work into several sections to avoid the need for tachos, but it would be difficult to do this as only the X9 calls into Peterlee Bus Station, and it wouldn't really be feasible to split the X10 anywhere.
Peterlee A19 Slip Road would not right as a destination for the X10.