Thanks for the clarification. A part of me wondered if you were asking me to compare a 40 year old tire to a 10 year old tires - and that was going to be difficult! Im glad its current tires.
OK, on to the question. What's different? Actually not much.
First, the steel belt consists of 2 layers of rubber coated steel wire, with the wires running parallel to each other in each layer. If you were to look through the 2 layers, it would look like a cross hatch pattern.
But those are the same to each tire, the only difference is that the wider tire has wider belts - and within each tire, the belts are the same underneath the treadface, except for the ends - meaning the strength of the belts are the same throughout either tire except at the ends - no difference.
But there is a difference in that the wider tire has wider belts so each individual wire wraps further around the circumference of the tire. I don't think that makes a difference in how the tire behaves, but it is a difference, but probably in the wrong direction for your theory.
So let's look at your assertion that lower profile tires get more pressure. According to Tire Guides, 2010 Honda Accord. It came with P215/60R16 94H at 30 psi and P225/50R17 93V at 32 psi. If I do the math, the load carrying capacity of each is the same - which would explain why there's a difference in specified pressure. But the Accord also came with P235/45R16 94V at 34 psi. That seems to be the odd man out, but I note that Tire Guides says this was only for the EX-L Coupe V-6, and that for the 2011 and 2012 model year, that same entry is listed as 32 psi. That's doubly odd. Can't tell what is going on there.
Maybe we could get some insight if we looked at the Civic. In 2010 it came with P195/65R15 89 S &H at 32 psi, P205/55R16 89H at 32 psi, and P215/45R17 87V at 32 psi. Huh?
What about the Accord in 2013? 205/55R16 95H at 32/32, 215/55R17 94V at 33/33, 235/45R18at 33/32. That doesn't seem to follow any pattern at all!
So I don't think your theory holds up.