I like how tidy and consistent that feels, however... what’s the proportion of services that already run doubled up and there are about 450 seats on a CC HST, vs 400 on a doubled up 4+4 formation.
Given the chronic overcrowded use of CrossCountry that I’ve seen in peak in the York-Leeds/Doncaster-Sheffield-Derby-Birmingham corridor, I don’t think 7/4+4 car formations would be sufficient and suspect the step change that comes with 5 car 802/804 type units running doubled up in the core during peak hours would be more sensible longer term...
I don’t think that means the 22x units are doomed, they just need a better home on lines where there are limited advantages to having a bi-mode unit - My gut feeling is pushing these units into regional express service use (coughs Northern Connect), replacing regional 170/185/195 type units, to enable cascade of these units to replace the remaining 1980s 153/155/158/159 on local stopper services. There’s still 15-20 years in the 22x fleets, an new engine pack, ful interior refurb and perhaps some length changes, maybe limit to 100mph would be a step change for the northern regional express services.