I mean, that's pretty much what the current timetable involves. Eastbound the Huddersfield-Leeds stopper sits at Dewsbury waiting for the Scarborough service to overtake it, westbound it uses the slow lines between Mirfield East Jn-Heaton Lodge Jn and sits at Heaton Lodge Jn, again waiting for the Scarborough to pass.But it would still mean a much slower stopping service, and a fantastically complex timetable with little room for failure and recovery.
The margin for 'pass to depart' is actually less than 3 minutes in each case - it's 1½' at Dewsbury and 2' at Heaton Lodge Jn - but it still results in a timetable highly liable to delay.