clear silouhetting with realistic proportion and character
Obviously you also didn't read their paper on left 4 dead design, they use the exact same technics, and it work for more than cartoony character, it work for everythings.
Actually you define identity with that.
I had already read that too and:
Because of this issue with the medic beam and a number of other similar challenges, the team decided to rethink the game’s art direction. The team enumerated all of the gameplay problems that more deliberate art direction could solve, right down to the specific details of the most outlying weapons, characters and objects.
From this list, the ''Team Fortress 2'' team was able to extract high level goals for a new art direction. First off, the new art direction needed to be exaggerated, to match the over-the-top combat style of the game. It also needed to focus on incredibly unique characters, yet still ensure that the classes looked like a cohesive team when shown together. Additionally, the art direction needed to support a variety of unrealistic weaponry and a variety of player goals, from collecting objects to holding territory.
Unfortunately nintendo use the same reason to justify wind waker and skyward sword. It's not much "holding to some ground" rather than solving gameplay problem. You may had pick killer 7 for a better stylistic argument.
But this is really how you make breakthrough in style that is meaningful and not a gimmick. That's how art use to evolve, by solving problem, whether it's a pragmatic problem or an ideological stance, everything in the art should be the statement that answer to that initial problem.
Valve said they needed a game that: Stands out from the rest, doesn't look too hardcore/and can easily transmit its visual information.
That's pretty much "holding to some ground"
it was never the playtester, it was a conscious decision.