You said, and I quote:
"They are not going to out execute or beat this PHX team in close games".
Game 4 was the first game where both teams were within a couple of possessions of one another down the stretch, and the Bucks were the ones who came out on top, because they executed on both ends of the floor, to a far greater degree, that it wasn't even remotely close. With 5.30 remaining in the 4th, the Suns only had ONE field-goal for the rest of the game (not counting the two buckets right at the end when the game was over); now, over those final five minutes the Bucks' scorers were:
Connaughton x 2
Giannis
Middleton x 3.
And the thing you're failing to take into account with this too is, even despite Middleton being the closer on the offensive end for the Bucks, the truth is, Giannis is still the most dominant presence on the floor, at all times. Over that aforementioned period in the closing stages, he single-handedly broke the Suns' offense, himself, making two blocks, a steal, and blowing up their PnR actions almost every single time he was in the play. This is why despite CP3 and Devin having deeper bags than him, doesn't mean that either of them have more impact. After all, this is the latter's first playoff run in his career, and the former's inhibitions have always reared their ugly head when the going gets tough in the playoffs.
It's not as if Giannis has to go through a similar scenario with Durant again, where he isn't the one and only big dog on the floor.
I think you were oversimplifying this for the simple fact this Suns squad had never really been tested down the stretch, regularly, like the Bucks have in this postseason. And not just this postseason either, because Milwaukee has been in these situations in prior years too, with relatively the same makeup of players, and that's where they have that advantage. All the Suns have to fall back on is whatever CP3 has done.
Milwaukee have the upper-hand if only for the fact that they have Giannis, and the Suns don't have anyone to match him.
Now, of course, this is reliant upon him needing the likes of Middleton and Jrue to come through in the clutch, but they both function on Giannis' energy and will on the proverbial a rising tide lifts all boats. We all saw last night with Devin and CP3 fighting over possessions and neither of them looking comfortable, where even despite the Bucks not always winning close games, they are almost always are on the same page, because they all know their purpose and the hierarchy with the situation of the game.
This is why I kept reiterating that the first two games were giving folks a false reading on how the series would play out, because one team was simply playing above their talent level vs. the other team still functioning properly, but weren't hitting their shots when they needed to.