I think you have hit the nail on the head. Faced with the original plans and a multi-million pound cost and additional planning permissions in order to relocate the Athletics Stadium, I think that Foley has probably issued a brief to architects asking what could be achieved utilising the training complex alone.
The answer is an 18,500 capacity stadium, possibly 22,000 plus if the south side (adjacent to the Athletics Track) is a double decker stand. When you think how Brentford’s ground is squeezed into an awkward space, it is clear that any half decent firm of stadium architects could come up with a solution to fit the space you’ve illustrated so neatly above.
As at Brentford there’ll be a high proportion of premium seats as Foley has said. I could be wrong, but I think he mentioned the Athletics Track in one or two early interviews but hasn’t referred to it more recently.
The land the club owns at the south end of Dean Court ( roughly everything south of the line of the south stand penalty area) would provide the main approach to the new ground. Structadene would be happy with that because it would help them to get planning permission for housing on the rest of the site, which would no longer be big enough for a sports stadium.