how can you know that? Dame isn't as good as Giannis, but he's pretty good and always commands the attention of the opponent's best perimeter defender. And, in Portland's offense CJ has free reign to do what he wants and play "his" game.
even if he did get some kind of bump in his numbers in Milwaukee, there's no way his TS% goes from .536 to .626, or his winshares/48 goes from .089 to .170
it depends on how wide a variety of stats you are using in a comparison and if there is any consensus in the numbers
personally, I'm not convinced that Brogdon is better than CJ; it probably cuts the other direction. But if CJ is better, it isn't by much of a margin. There's not a lot doubt in my mind though that Brogdon would be a better fit with Dame in the back court, and that if the players were switched the Blazers would likely be just about as good as they currently are
one thing that hasn't been mentioned is that Brogdon will be RFA this summer; so he's about to get paid. The Bucks have some decisions with both Brogdon and Middleton being free agents