At the May timetable change last year, we were promised by TPE that special stop orders would be used liberally in the event of disruption... no signs of that today, so journeys like Huddersfield to Batley are getting only 1tp2h. This wouldn't be so bad had Arriva removed their bus service between the two towns. The Scarborough service is still running non-stop to Leeds when the stopper it overtakes at Dewsbury isn't running this hour. Therefore a stop at Dewsbury could be accommodated with only a couple of extra minutes delay and no impact on following services.
A further question is why this SDO system has been introduced before it is ready, and when 6-car workings are so rare and most (if not all) stations can handle 3-car 185s. It's an unnecessary complication at the present time. There are several Northern units in the sidings at Huddersfield, which under BR could be brought in to fill some of the gaps caused by the 185 issue. Fair enough, the 195s won't have trained crews available but there's a 144 behind them that is better than no train at all.
When the public sector does things to a cost, we get Pacers... but when the private sector does things to a cost, we get Pacers being retained longer than their design life, and disruption when things go wrong, which can't easily be mitigated.