Yep they are currently, but having anything fast on the Trent Valley not running on HS2 if everything goes through Colwich is not the best use of capacity. Keep the stopper and nothing else.
Surely it depends on the total number of services. As long as the royal number of services doesn't increase beyond Handsacre, then it's not an issue.
It's why there's so much talk of HS2 services running in pairs and splitting at Crewe.
Also I'm not overly convinced that the reduced capacity from the HS2 (200m) stock is as big an issue as some are making out (yes it's not ideal and yes it's a great way of pointing out just how short sighted cancelling all of phase 2 is).
For example, until the recent refurb the /1's would have seen a 39 seat reduction in capacity whilst the /0's would have seen an increase in capacity of 81 seats. Given that 1/3 of the fleet is /0's on average (assuming every diagram has an even mix of train lengths) there would be 549 seats.
Yes the referb does increase that average seat count to 574 and yes at peak times and potentially on certain routes the seat count would be higher. However, where is most likely to be an issue is at Euston, where the use of pairs of units could help with load management.
Therefore it's then a question of which other stations could it cause an issue at and on how many services.
Then it's a case looking to see if there's some easy wins.
For example, lengthening platforms at Crewe and Carlisle (maybe Preston and Warrington BQ too) to allow longer trains to get through more of the constraints so there could be 1 unit per hour to each of Glasgow and Edinburgh (by splitting a diagram at Carlisle) rather than the current 1tph to Scotland with Glasgow missing out when the service goes to Edinburgh.
Likewise if Manchester could have a 400m platform there could be a pair of units with (say) the rear unit having the announcement that it's calling at Old Oak Common and Manchester Piccadilly, whilst the front unit calls at stations such as Stoke on Trent. Both units would run as a pair all the way through, it's just that the rest unit wouldn't be advertised as stopping at other stations (although there could be a local door exit for any passengers in the wrong portion).
The bottom line is, that ultimately we want the cancellation of phase 2 to cause issues and it be seen as a very bad decision so the rest of HS2 gets built.
Yes it may delay the opening of the full route, but if was shown that it was the right thing to have built, then the next big rail project could be easier to deliver.
Images of people sat in the floor of HS2 services due to a lack of seats within (say) 10 years of phase 1 opening (as demand for rail travel sees significant growth - just like the Elizabeth Line) even with some stocking plaster fixes, then this could be good for more rail investment. As it will show that if you provide more capacity (Elizabeth Line) or faster trains (HS2) then add long as that's on routes where there's potential for significant demand it's more than worth the investment.
Whilst that may not get a new Cornwall mainline built, it could get more cross city routes built for Manchester, Birmingham, Leeds, etc. Likewise it could see HS2 (full Y) completed and other HS lines built.