Im pretty hesitant to bring wr into this, i dont think valla is s tier either but it feels pretty clear to me that she sees a lower wr because ppl are playing her and getting blown up instead of positioning correctly. I feel the same way about varian dual wield's higher win rate
I think that when the win rate disparity is SO high though it need some further explanations, if only to validate the list because otherwise people are going to look at it, pick Valla, and then wonder why they aren't crushing noobs every game.
I'd also say that if a hero is listed at S tier and the reason she isn't dominating is because she's easy to blow up, then she isn't really S tier. I mean, we've had objectively overpowered, S tier heroes in the game before - li-Ming, Xul, Samuro. They really *were* S tier, and the reason they were overpowered was because despite their weaknesses they were so strong they were still winning games more often than not. Does anyone really think Valla is near that state right now?
(Also to say, I don't think EU or Kor teams are valuing Valla that high from what I've seen).