This is one thing where I'm afraid I must disagree, I do think first are that stupid, you should see how they recruit their Engineers, if you have any actual real engineering skill or behave like one (asking for clarification before proceeding) you've got no chance of getting the job, even worse if you're not a protentious prick that has no ambition other than becoming a manager...
To give some background to this, I was being interviewed by people on their APEDS scheme to become a chartered engineer, this is an accredited pathway layed out by British Rail in accordance with UKEC and IET/IMechE guidelines, and should take four years for a MEng candidate and five for a BEng candidate, the interviewers had been with the company for 9 years and had not fufilled UKSPEC (UKEC Specification for a Professional Engineer) because all they did was managment.
Because First Group's managment favours wet behind the ears no skill other than pure accademia and/or psudo managment skills (all this new age modern kak that is really irritating and doesn't have any foundation in real managment) I really can see the whole managment team not realising about the body profile of Class 390 and 221 stock and proceeding to order 3+2 seating for standard regardless, or in some other way reduce, significantly, the current quality of Standard Class so it would only be used by the subclasses of society that are highly price sensitive (Students, Young Families, Unemployed, SDNW etc.) and the 'club class' that I can see being similar to current standard class with a free diet coke would be a required upgrade for any passenger who is not price sensitive, resulting in an artifically inflated standard class, now club class and packing them in in 3rd class.