Good OP Musketeer..
It's hard to argue w history. But I will say this, it would have been damn near impossible for those old Phoenix teams to crack the top ten in defensive rating w Nash and Amare needing to play big minutes. They both sucked on D and it was extremely difficult to keep them from being the focal point of the other team's offensive attack when they were out there.
Lets see what Coach can do w better defensive playerz.. We seem to have a squad now that can play a more balanced game offensively and defensively.
Billups - an aging but solid, smart and vocal defensive leader
Fields - the rook flat gives his all on every possession
Melo - He's capable of good 1:1 d, but he needs to work on focusing on every possession on on that end. Sometimes he gets beat back door because his head's not in to it. He's capable of the odd steal from the passing lane, or by cheating off of his man to strip the ball from a player who's just received a pass.
Amare - He's become a better shot blocker- 4th overall in blocked shots. He talks more on the defensive end now. He's now a capable help defender too. He's just better now at the defensive end. He understands now the importance of him being a better two way player.
JJ- He's a extremely capable help defender. He can defend the perimeter well. He's not the best post defender. He's good at clogging the lane and drawing charges. He communicates very well on the defensive end.
TD - excellent hounding 1:1 defender that will continue to improve w more experience. He's still sometimes goes under screens. Needs to work on his p&r defense.
Turiaf - displays all out hustle every possession. Very vocal. He's a capable shot blocker.
Mason, Williams, - are very solid defensively also..
The point of the above is to illustrate the potential this team has defensively. A solid defense starts, first and foremost w the playerz a team has. Having a guy like Billups instead of Nash makes a world of difference defensively. Having Amare improve his shot blocking and overall defensive mindset also makes a significant impact.
Greg Popovich can be the greatest defensive coach in the world but if he had Nash, who can't stay in front of anybody, and a young Amare who cared nothing about D instead of Parker and Duncan, he wouldn't get the same results. Pop also had guys like Horry, and Bowen - great individual defenders.
The crux of the whole discussion is that you can't have a top ten ranked team in d-rating while having two players that are extremely integral to the team's success due to their offensive prowess, who can't or won't play D.
Mike D came close w that 13th ranked d-rating team, but Nash and Amare were basically too much to overcome. Lets see what he can do w a better, more focused overall group. Next season if Coach can't get very close to (atleast 11th or 12th) or in the top 10 in d-rating i'll seriously second guess his long-term viability as well. He also needs to expand the rotation, which i've been saying for a while now too..
One last thing, imagine if you take Nash off of those old Phoenix teams and plug in Chris Paul. How much better would they have been defensively then? I think a couple of those teams could have cracked the top ten in d-rating easily due to Paul being a much better two way player that you wouldn't have to hide on the defensive end. See what i'm saying..? As much as it's about Coach it's more about the playerz.