They make this point a few times in the comics , usually when he's sparring with Wonder Woman and she hands him his ass repeatedly because she was raised for combat and comes from a straight up warrior society, and has near equivalent tier strength to him apparently.
As for this movie, it will once again probably show the kinds of characters and driven pieces Gunn can do well, probably a lot better than Superman did. But I still think it will struggle because the core audience of Superman fans are for the most part still seemingly pissed at how he handled that movie, and he needs those people to show up. Because the Peacekeeper/Suicide Squad/GOTG crowd probably isn't.
