you're missing a point: their look should be based on their skills, not their skills based on their look. I dont wanna tell you how to draw or desing anything, i'ts just my option.
you really think a 19-year-olds look like very skilled assasins? and a 9-year-old looks like a person who could actually carry heavys's gun? I'm just really bored how there have to be "prettier and better" versions of everything. Every time i want to someone to desing a women-version of something (for example tf2) i always get a slut-version instead. Where is the unique idea of women? Where is the real women-version of a man? Is it really true that realistic women-versions of tf2 are not cool enough? Because they would not be young (except scout) and sexy?
The female Heavy Weapons Guy (Heavy Weapons Girl) is clearly meant to be ironic, and not meant to be taken seriously. Just like in the actual game, the character designs aren't meant to be taken seriously. Do you honestly think if Valve wanted the character designs to look serious and believable, they would have made the Soldier wear a helmet that covers his eyes, or make the Medic wear a doctor's gown on the battlefield? Do you think they would have made Spy wear a suit and a ski mask? Since the real character designs aren't meant to be taken seriously, why should these versions?