That was what drove the 333s to Doncaster plan: that line needs 4-car trains, so the plan to run pairs of 3-car 331s to replace the Dusty Bins meant 333s had to do the Doncaster run.Never say never though plans change and it may end up that when the 4 car 331s are swapped with the 3 cars the 333s might become the train of the Donny line
One plan possible could be to run through services from the Airdale line to Doncaster as 6 cars which has been mentioned.
Doncaster Platform 6, where they'd usually go from, would be too short. I don't think 7 is much longer, and using 4/8 wouldn't be practical.I can’t see that being a good idea at all, all it’ll do is spread delays from one area onto the other, while adding further risk at Leeds west end. Perhaps even dafter an idea than the long distance TPE locals.