The guys get to have masks and scowls and distinction

Females are pretty distinct too. Tracer has goggles, Widowmaker has blue skin and some other goggles going on, Symmetra also has some futuristic headset thing going on, Pharah has a helmet, Mercy has halo and Zarya has a scar. Their facial features might not look as unique as on the male side but it's mostly because there are essentially only two straight up human males that have faces, with pretty significant differences all thanks to facial hair and cigar.

I would not call McCree smooth-skinned with that animal on his face

Well, you can have smooth skin and still have facial hair.

all have variation, that variation is way smaller and they STILL all have a slim, beauty-standard conforming bodies

That seems to be a part of their cartoonish stylization. I'm sure it will be a while until they stop announcing new characters since that's seems to be one of the selling points. They already have one fantasy race in so it only makes to have female version or something similar added in to increase variety.

I don't get why you're arguing that dwarf physiology matters somehow in this conversation. You were referring to real-life human biology, and dwarves are made up, their biology can work however the author wants.

Yes and not really. Anatomy is one of the things that makes dwarfs what they. Remove muscle and fat - you get a bearded gnome/halfling. Remove small height and it's just a buffed human. And Torbjorn is almost template dwarf. Engineer, has huge beard almost half his height, huge nose, large limbs, developed musculature and big belly.

You were saying that Overwatch women can't look a certain way because it's not biologically feasible for real humans (which you would, again, be wrong about, because human physiology is not simple like that), so comparing them to fictional creatures doesn't work. And again, you acknowledge that the Overwatch world already is unrealistic or at least works with its own set of rules, so basically everything you argue based on real-life stuff is meaningless.

I wasn't arguing about realism or how real something is. Just basic anatomy and extent to which it's stylized. If you create something that looks exactly like human it means it should look and behave like one. Overwatch is cartoony and stylized, but it's not stylized to the point where human anatomy can be blown out of proportion. Even dwarfs just like any any fantasy race or beast follow basic anatomy and physiology, there's even a books dedicated to that.

I don't get what in the Overwatch art style stops them from giving women big noses or wrinkles or stronger jaws or anything else that would distinguish them from each other.

Nothing, it's just that so far they haven't made a character with wrinkles, big nose or stronger jaw. Even though I'd say they are quite distinguished and recognizable as it is, simply because of talented artists at Blizzard. Also same argument can be made for all eternity because there are beyond many faced on Earth that have something distinctive about them, and yet somehow aren't in Overwatch.

If you argue that they need to keep the faces feminine

I don't, if they ever make a grizzling chunk of a female in sci-fi armor it's only natural to expect quite masculine faces, GWS kind of nailed the look with their sisters of battle miniatures. If they make a feminine character though, it's only natural to expect a feminine face.

Why can't there be average looking women?

Because these are not average women, far from it. Same goes for males, gorillas and robots.

That is my literal point. I want these characters to have things that stand out, I want these characters to actually look properly different from each other the way the male characters do.

No, I didn't mean it in "Damn that character is really unique and stand out for me", I meant in "Did you steal this asset from another game you fuck?"