Just on the 6.27 am new pudsey to leeds
There's a problem with services before the morning rush hour, before the full daytime frequency kicks in.
From New Pudsey, there's a...
...and then a roughly fifteen minute service.
(there's an 05.20 to Bradford Interchange, where you can walk to Forster Square and catch a 333, but I think we can safely ignore that)
So no huge surprise that the 06.27 is so busy; its the first service from Halifax, Bradford etc into Leeds.
Similarly, the one "northern" entry in the top ten list of busiest services in the UK (measured by train capacity) is an early morning service from Huddersfield into Leeds - again before the "daytime" frequency kicks in.
(sorry for trying to look at the facts and not just jump to assumptions about Northern/ 153s/ DfT etc)