I really believe the original sin lies in that moment when Space marines got boosted that way.
Picture from Solegend
And isn't it just great ? having room for both ? Giant mutic mass produced killers along humans with all the characteristics of humans in power armour ?
I have to say it's relieved me of an issue I didn't know I had. I can now fully enjoy my C100 marines and their pathetic aesthetic without having to care about what legion/chapter/markings/whatever. And I can have a fistful of gigantic freaks on the same table !
Maybe the only common point between the guys in the 2 pics below is that they have a power armour...
Time to take a big fistful of M&Ms and eat them without caring of the colours you picked.