I'm not convinced Eric would be much of a head coach (hard to win with everybody mad at him
), but I think his main point is sound. Most NBA type coaches have a lot less impact on teams than is generally assumed. The NBA is a player's league and the team with the best players typically wins.
Take Larry Brown (please!). He is a huge success in Detroit and a massive flop in New York. Did he spontaneously forget how to coach or did IT simply put together a really awful team?
I tend to look at coaches like jockey's. A great jockey may be difference between winning and losing a close race, but won't make a bad horse a winner or keep a great horse out of the money.
Like the jockey, the coach needs to be a good fit for the team's personnel. Don Nelson is a hall of fame level coach, but totally flopped when trying to coach Patrick Ewing's Knicks. The players simply revolted against his style. In Dallas he had a chance to put together a team that fit his style and had a lot of success, but had the bad luck of coaching against an unstoppable Laker team.
Would a different coach do a better job with the current Suns personnel than D'Antoni? Perhaps Nelson, although Don has his share of blind spots to match D'Antoni's. I can't think of anyone else who could do better with this collection of players - but I can name numerous guys who would do worse.