Fighting does not in and of itself denote toxic masculinity, just like Agent Z said. Rather toxic masculinity includes, among other things, a certain approach and relation to violence and violent behaviour. The Geek feminism wikia has a decent and short overview of various
ways that toxic masculinity expresses itself.
My ideal Steve is rather close to the movie Steve. He does not like fighting, even though he is good at it when he has to. (Which is different from Diana, who I imagine as someone who loves a good fight, and at times could struggle with or feel ashamed of that feeling.) Both are good at talking their way out of conflicts, but they use slightly different strategies. Like Diana is better at mediating a peace treaty, but when you want to get a hundred refugees besieged by ISIS to safety, Diana is more likely to simply punch herself to a solution, simply because she can do so.