I think most of the blame lies with Avery. I'm becoming inclined to agree that he may just not be a good coach. His playbook seems to be to try and do things the Spurs have done. But then mess with it some so he doesn't get accused of simply copying Pop. It would explain why he keeps trying to shoehorn Dirk into a role he had not and never will play. It also explains why he goes with putting Terry as 6th man and then s with it.
He doesn't seem to have the patience to just leave things be and see how it works out. We know Pop likes to tinker in the early season, so maybe that's why AJ does it too, but he goes too far. Too many lineups, not enough to see what's happening, you know? Also, things seemed to go better for them when he kept their old offensive schemes in place and simply added killer D. Now that he's ing with the offensive schemes, it's falling apart.
Yeah, it's December, and no, they don't need to go balls out to win. But the difference I see between the Spurs and Mavs is that the Spurs are still held accountable for lazy play. A bad pass or failure to cover your man will get you pulled in the early season. You will see playing time cut back if you sleep walk through the game (ok, admittedly Duncan has slept through a few games, but he turns it on when needed and has proven he can turn it on). The Mavs don't seem to have that accountability right now. They seem to have no motivation to win - simply trying to rest up doesn't mean you don't play hard or efficiently - it means you play fewer minutes. Additionally, Avery doesn't seem to have given them a leader or someone to believe in, and further is giving them conflicting messages (It's ok to play lazy ball, because we are resting. Wait, no, we are trying to win every game and play hard. Which is it?).
The Mavs haven't really proven that they have another level that they can simply flip on when needed. That would concern me if I were a Mavs fan. Too early to jump ship on the team or call them out or anything, but I'd be watching to see how the development comes along. Spurs are developing and getting better, albeit slowly. Can the same be said of the Mavs?