EGD,
That simply isn't true, they are 4-4 against Dallas in the regular season the last 2 years (2-2 each season) and lost in the playoffs in 06 4-2, losing by an average of 9.75 ppg. They were 3-7 in the regular season against SAS the last 3 seasons and have lost in the playoffs twice. Admittedly they didn't have Amare and Diaw for a game in this season's playoffs, but they clearly don't have success against these two teams and the main reason is their inability to stop Duncan and Dirk. The two of them destroyed Phoenix in the last two playoff series.
He may be one of the best young talents in the league, but they are getting back someone who is currently better. They are fixing what is probably the #1 issue stopping them from advancing. KG is only 31, they aren't trading for a geriatric Karl Malone like LAL did. He has 3 more elite seasons left.
On a short term basis, this is an upgrade and an upgrade from the one most vital problem area. Their window is short, if this were a young team like the Bulls, maybe you don't do it, but when Nash is done, Phoe is done and Nash will be done before KG. Considering Marion may leave after next season, they may only have 1 season to make a run and, as far as I can tell, they can't get any farther with Amare and they may be able to with KG. IMO, as I said, you can't keep going to battle with the same guys when they have proven for 3 straight years they can't get it done.