Yes, I saw him fight against Kim and he beat him easily and quickly, but it was not a big test, so when he came to UFC I was still dubious, but his first fight he beat the shit out of Mir, I know it only lasted a few minutes but he was dominating easily and that stupid moron ref Steve Mazzagatti stopped the fight when Brock was hitting Mir, saying that Brock was hitting the back off the head, which was such a BS call. I could see Brock would be dangerous for anyone.
Then he beat Herring to near death, then stopped Couture, then beat Mir to death in the rematch, but then he had that huge stomach illness where he had to have surgery, it took a lot out of him and he nearly died. Came back and beat Carwin, showed huge heart in it and never ever quit, then tapped Carwin out. He then was dominating Cain, if you actually watch that fight Brock was winning, took Cain down twice, but then Cain caufght him with a good right and then Brock went spinning. But this was all post the surgery.
I still thought if Brock comes back he can beat a lot of the UFC HW's, a lot of them are awful. when I was watching Stipe vs Ngannou, I kept thinking if that was Brock on top then the fight would have been over ages ago and no decision, Ngannou had no clue what to do on the ground and he was doing everything wrong, you could see how raw and amateurish he was in the wrestling, Brock would have smashed his face though the mat that night I believe.