You are dishing some good stuff here Woody, or so it seems to me.
The "vortex" pattern that you suggest is smart.
I only have one fan in my 5'X5' tent, but my lamp is ducted and
I am near the coast, so I am cool heat-wise.
I kinda lucked into a something similar to what you suggest, and
I thought that I might share the idea, to see if it survives scrutiny. :0)
I positioned my fan against the side of the tent, in the middle of one
of the sides, pointed slightly downward, so that it blows along that side
of the tent.
This makes air swirl down the sides of the tent, and all of the 36 plants
of my SOG get fresh air. Once the rotater broke I had to come up with
a way to avoid just always hitting one area of plants.
It is a full sized room fan, 16" I think, so I have strong airflow.
Onward and upward,
JD