I imagine he's getting at the fact that load range E tires have a 10 ply rating, not that they actually have 10 plies.
I was too quick to call them a "10 ply" I know they are rated for like 3600 lbs, E rated... but I don't know how they are actually put together. I know they are E rated, 80 psi.
But I also know that there's a chit pile I don't know about tires. I'm amazed at how much there really is to good tire mounting and balancing.