Sorry Clive, not read through those threads, just passing by.
From what I've learnt along the way, I think along the lines of, the plants haven't got the legs to run to co2 and nutrients so the flow is required to circulate those elements to the plants.
High light, Co2 enriched or "high tech/energy" tanks require more flow as the demands are greater where as in a lower light, non co2 enriched tank, the demands are a lot lower so you can get away with less flow. A perfect example of this is the ultra low tech shrimp bowls with zero flow/filteration.