Imported Cheese is exaggerating a lot in his life streams. In his tierlist videos he makes clear that he goes for a non-speed but still efficient run. Meaning knocking out the opponent with as minimum efford as possible. He does give credit for set up, but it better pays off and you don't have to go +6 to sweep.
Not to take away too much off topic, I think I will write about my past experience with in-game Azelf in DPP. I don't remember which one but I know that whenever I could not one shot an opponent, which is possible if you grinded and taught it good offensive moves, this thing dies usually.
Uxie is the exact opposite. It doesn't die but you slowly chip away health. If you don't get to set up +2 with X-Items and your opponent has moves to status you, you are screwed. It is a real waste of time. You can win eventually but to me it was a waste of investment using this Pokemon.
On the contrary, I used in a Platinum run a few months ago Mesprit and it pretty much helped sweeping the rest of the game. It might be the worst competitively speaking but for a run where you want to waste as little resources as possible, it is ideal.

Not to take away too much off topic, I think I will write about my past experience with in-game Azelf in DPP. I don't remember which one but I know that whenever I could not one shot an opponent, which is possible if you grinded and taught it good offensive moves, this thing dies usually.

Uxie is the exact opposite. It doesn't die but you slowly chip away health. If you don't get to set up +2 with X-Items and your opponent has moves to status you, you are screwed. It is a real waste of time. You can win eventually but to me it was a waste of investment using this Pokemon.
On the contrary, I used in a Platinum run a few months ago Mesprit and it pretty much helped sweeping the rest of the game. It might be the worst competitively speaking but for a run where you want to waste as little resources as possible, it is ideal.