I'd be more inclined to suggest a goalpost arrangement on a suitable minimum 1200 x 1200 x whatever depth to good ground excavation with a minimum of 600mm concrete mass fill. Point load distribution etc etc.
I'm not a struccy, only a lowly builder of 35yrs on the job and I'd not argue directly with an SE. I would however ply him with questions.
I'm getting the impression you'd like to get him back on the blower and ask him more ??