Keeping it very brief x 17 sounds right for northern. Cannot see x9 being being done at Doncaster other than for further wmt use ie for extra trains as per extra predicted growth in west Midlands by 2026. As per the plan for the devolution for wmt by then to become separate from lnwr and wmt to become part off the devolution and controlled by the west Midlands local authority controll. And these might well stay.
However all said and done anything can happen and does so let's wait and see. Because come tommorow etc, it might well change again.