Depends on the players also. I think strictness and focus can come from within the team also. In general I think there is too much focus on the coach. The player has to be able to do it, and most championship teams seem to have the capacity to get it done no matter who the coach is.
The problem with a strict coach is that sometimes his ego will get in the way. But I'd rather have that problem because it's a lot better than 25 guys not being on the same page, even if it's the wrong page.