But the 730/0s in the West Midlands will be used to displace 350s for work out of Euston. It’s most likely that the Walsall to Wolverhampton and Rugeley Trent Valley to Birmingham International services will see their 350s replaced by 730s.
If I recall correctly, last time I heard, the 730s that LNR are getting will be used on the Euston-Tring/MKC stoppers and Euston-Crewe, with some 350s supplementing them at peak times.
Euston-Crewe requires 5 diagrams, so will likely need 10 units (1x5.730 would be a very bad idea, 8.350 can be full and standing on that route regularly).
Euston-Tring/MKC requires around 5 diagrams, off peak, I don't know the exact number, but that's what I made out after a look on RTT, (if anyone could quote the exact number that'd be a hude help!), so will likely need 10 units too, leaving 16 units spare each day.
If they were to be used on Birmingham-Liverpool services that'd be another 3 diagrams, though I don't know if the platform lengths are suitable for 10.730, and 5.730 may be too short, Birmingham-Crewe could be another possibility, and would require a similar number of diagrams, maybe one less. I spoke to a WMT manager a few months ago, but can't remember what he said other than Trent Valley, WCML South Stoppers and something else that I can't quite recall.
In any case, their use around Crewe comes with a few issues, most notably that none of the southbound bay platforms at Crewe can accomodate a 10 car 730 as far as I'm aware, so would most likely have to use a through platform.