Miller won the starting job over Blake halfway through his first season. It was only Nate's incompetence that kept Dre benched as long as he was. Once Miller got the starting job he never lost it again. Brandon was decidedly more effective when he had two functional knees, which was sort of true in Miller's first season. (Roy logged 2400 minutes in Miller's first year, and 1300 in his second.) Notice who wasn't playing in that first video I posted where Roy has his last hurrah? Blake. Because we let him go to the Lakers despite what a great fit he supposedly was.
You don't have to believe me though about Blake. Just look at his career. He had two years of starting and never got the role again. And rightly so.