I don't know about crushing big hands, just that I own both brands and that's how they stack up for me.
The No3 COC is so hard I can't hardly move it. Even Mark Felix from WSM had to practice for a week before he could do an "unofficial" No3 close.
I'd also say that because the HG are cheaper,they are probably less standardised meaning that there is probably a fair difference between different grippers of the same rating.
I see what you're saying.
Either way, I love my heavy grips...and enjoy the feeling of having so much power in my hands