I usually agree with you Esjay, but no, it absolutely does not. Duncan has been on much more talented teams and much better coached teams.
KG's best shot at a title before he finally won one was in 04 I think when he lost to the Lakers when they built their last run team. He did everything he could in that series, but the team just plain wasn't good enough to win a championship. You can't say that about most of Duncan's teams, point blank. The Wolves got killed in that series because they couldn't stop Shaq. You can't expect to stop Shaq with Michael Olowakandi, Ervin Johnson, and OLLIE MILLER. Really, not even going back to when Duncan played with a HOFer in The Admiral, but Ollie Miller makes Rasho Nesterovic look like Hakeem Olajuwon.
I don't really like the whole rings vs. rings argument. Obviously, you have to take that into account when figuring how great a player is, but directly comparing two non-comparable results because the situations are different and acting like they somehow were. It just doesn't sit well. Duncan has been on some really good teams. Manu, Parker, Bowen, Stephen Jackson, Robinson, even Robert Horry. And who were the guys that finally gave KG the "help" he needed? An old Sam Cassel, Latrell Spreewell, Starbury at the start, Wally Szczerbiak?
It's not at all like the Spurs just so happened to be better teams than the Wolves most every year because Duncan was better than Garnett. They were well put together teams from the start and KG's teams almost always had glaring flaws.