There will only be an extra STD coach where there are 3 1st class coaches now - the sets with only 2 1st Class coaches will have half a coach declassified to STD. So there'll be a minimum of 1.5 1st class coaches - and those with a full buffet will have two.
So, will micro-buffet sets be:
43 - TGS - TS - TS - TS - TS - TSMB -
TC‡ - TF - 43? Or will the micro-buffet become a composite coach?
And will the other sets have standard class in the buffet car (like IC225s) and be formed as:
43 - TGS - TS - TS - TS - TS - TSB - TF - TF - 43?
Personally I think having first class seats in the buffet car, but with the buffet end coupled to standard class, is a good idea. I also think 3 full coaches of first class is too much, it should be 2.5 or 1.5 (with the other half of the .5 being the kitchen/buffet). So the IC225s should be formed like the
GW▸ IC125s currently are (ie. 2x FO, 1x FirstClassBuffet, 6xTSO) and
IEP▸ trains should be formed DTS - 5x
TSO▸ - FirstClassBuffet - FO - DTF (or 6x TSO at the cost of the FO) rather than the current plans to have 5-car sets and have the only kitchen/buffet on the entire set tucked away in the first class driving vehicle.