Added what I think some of them are below.
A 5 car
IET▸ - 324
A 9 car IET - 647
An 8 car
HST▸ - 522 to 575 (depending on layout and whether composite carriage added to 2+7 formations)
A 4 car 387 - 224
A 3 car 166 - 264 (after Universal Access Toilet was fitted)
A 2 car 165 - 159 (latest layout, with Universal Access Toilet and bike rack)
Taken out loads of quoted there for clarity and looked up ...
A 2 car 158 - 124 - 142
A 3 car 158 - 208
Mk 3 carriage ... up to 76
So looking at Cardiff to Portsmouth ....
currently 3 car 158 ...
208 .. goes up to 165 + 166 (total 5 cars) ...
423Suggestions of
... running a 5 car IET and it would only be up to
324... castle class HST up to
304so they would be a much lesser step up