Which current NBA coaches would you consider untouchable? As in, their current organization wouldn't let them go; not that the coach wouldn't leave.
For me it's Doc Rivers, Tom Thibodeau and Gregg Popovich. Probably Rick Carlisle too - he seems to hold a lot of respect in the Mav's org.
Hmm...Maybe Vogel. He's the one who's given most of the credit for bringing them back to where they are. Scott Brooks, as well, as he is the only coach the Thunder have had while good.