I agree, this is a tough one and the reason you will get many different answers. I think you will get diff. results at different pressures w/different configurations. On a straight blade hauler for instance, more paddle is on the ground w/less air but more susceptable to folding over as mentioned. There is prolly a point on the low and high side that equal out in traction. On the high side, the paddles stay good and rigid possibly gaining you better traction....you see what I mean. On a staggered, still holds true, the more air the less chance of paddles folding over on you. BUT.....when you air a staggered down, you get a lot more paddle on the ground than you do a straight blade.
I believe then going to a different tire, say a ripper, those paddles are so stout, you may not ever gain traction on the high end because they just don't fold over....I don't know this to be true, just trying to prove a point for arguments sake. I guess my answer would be, every tire is different. You may figure out a set of rules for a straight blade hauler, but those same rules may not apply to all other configurations.