This is great info. Thanks for clarifying. From what has been discussed on here about passenger loadings, 2+5 is definitely the way to go so it's great that the southbound platforms at the station at Inverness can accommodate them. Trying to do it all on Platforms 1 and 2 clearly wouldn't work.
Are the sidings at Inverness long enough to stable 2+5 sets in between turns?
Trust me, a 5+2 HST will most definetly NOT fit into Patforms 3 or 4 at Inverness - the leading power car would be hanging off the end of the platform, ahead of the signal. A 4+2 is fine though - the most you can fit into Platforms 3 & 4 is either 2x 170s or 3x 158s (eg, 6x 23m coach lengths).
Yes, the sidings at Inverness will take 5+2 HSTs (nos 6, 7 & 8 roads, beside the CMD were recently lengthened to take HSTs), also I've seen 2 4+2 HST sets stabled together in the Motorail siding (beside Platform 1) .
It's quite time consiming to shunt back & fore from the CMD though, but certainly possible