I reckon Chris is wrong or his argument doesn’t apply in most cases. I can feel the backwards pull of a big lorry or bus before it overtakes me on the open road, transitioning into a gentle tow as/after it passes.
Maybe it’s different in a race team with all riders in aero crouches and riding within centimetres of each others wheels. Kind of like doubling the length and weight of your car and fitting a second engine vs having two cars. Both engines would benefit, but only because the airflow is properly uninterrupted.
Probably not the case for most of us, most of the time.