I think the proportion thing is mentioned because it stands out. It would be as stark as making Joel have the build of Marcus Fenix, it would just look stupid in that setting. Joel just has mass and size, thick forearms, it's not as if he has his top off and has rippling muscles and a six pack
This fits the normal human man. This does not and would be equally as ridiculous as Joel's build
I mean that's obvious. The characters are built relative to their world. That's why other Gears are all big and chunky. It's why JCVD wasn't fighting guys like Arnie in Bloodsport etc. I mean you can visibly see the abs through her clothes here, the chest is basically flattened through low body fat and you can see the exact curvature of the muscle in the arm. She just doesn't fit the world and it looks ridiculous.
It's not that women can't ever be like this or aren't built like this, it's just in this setting it looks stupid for a series that's grounded in girtty reality. Why wasn't Tess/Marlene built like this? Marlene is actually ripped but at a scale that makes sense
This looks stupid: