Old thread, timeless topic.
A nail is not a nail. I have found that cheap nails have a terrible head diameter size variation, like from over 0.385 to under .325 in the same coil.
Frankly plywood and ordinary roofing nails suck - plywood does not hold a nail like wood. I don’t roof that often but if I was doing a plywood job, I would only use ring nails.
Ring nails are another matter. They grip like crazy. In wood, you will pull chunks of 2x4 out if you have to replace sheathing nails (not always but this will happen on occasion.)
Further, ring nails will grip in 26 ga galvanized which means yes, you can cover 1-by defects with “tin” - in fact this is supposed to be code in FL where they don’t screw around.
NOTE: HF nails are the cheapest and they suck totally as far as head diameter - but I am assuming a quality nail head diameter does NOT vary in size. But if name brand does, that will be depressing.