The Tank Difference in Role Queue vs Open Queue

What is the Tank Difference, with respect to their attributes, hp, etc, in Role Queue vs Open Queue?

You’d think with it being modes of competitiveness, the transparency Blizzard would provide would be more than nil. The reasons I’ve noticed a difference in the two is because I play both religiously and have “felt” the difference, and also because frankly my nerdy two-shoes remember something being mentioned along those lines in a patch notes far further than I care to remember.

Too much to ask for the detail to be noted in the ‘right-click info’ option that you can delve before entering the respective competitive mode?

Blatantly disregarded to keep things a mystery?

Blizzard just lazy af and change these numbers so often they figure lets not post this anywhere therefore never having to remember to change it after each respective change?