Winston is amazing for King of the hill maps is what I’ve come to find, and truly only works well if you have a good DPS to dive on the thing you’re trying to focus and distance heals for security.
One thing I see a lot of people mess up with Winston on, is that he’s one of those characters that’s meant to end fights, not really go and start them. I love playing him as that asshole who sees a character that’s 100 health or below trying to retreat back to the healer, because then they’re caught off guard and I have a chance to go get them and healer and pick them off.