first let me say that we should give memphis plenty of credit for making the thunder look worse than they are, which leads to these questions about westbrook - memphis is a flawed team, but they can beat anyone (and watching them, it makes me think that ainge's biggest mistake was not resigning tony allen).
i think OKC can't afford to downgrade one of their stars, the time for that would have come when they had more assets to spread around, maybe they could have gotten rondo and kept harden. that team would probably be better than the one they're fielding now.
OKC is who we thought they were - a team with 2 exceptionally talented perimeter players who dominate the ball but often fail to get their teammates involved. and as great a scorer as westbrook is, i don't think he's an exceptional ball distributor. OKC doesn't get the ball inside enough - and, arguably, they don't have anyone to give the ball to anyways. aside from their top-2, and maybe jackson, the rest of the team is a little passive offensively, which leads to a lot of perimeter shots. they need another slasher (like harden), or some kind of post player to open up the floor.
presti's biggest mistake was giving serge ibaka star money, that led to them trading harden, IMO.
and while they certainly had a need for a good big man, ibaka puts up stats but isn't the kind of "quarterback", like noah, KG, or marc gasol, that takes the whole team D up a notch. if you watch ibaka closely, he sells out on a lot of plays for blocks/boards/etc. he's just not as intelligent as the true elite big men are. he also has little offensive game inside. half the time he's on the court i don't even notice he's there.
let's flash back to 2011. at the time, OKC had jeff green, harden, ibaka, and the clips top-10 protected first-rounder (which at the time looked like a much better pick than it turned out to be, after the CP3 trade).
now they have an overpaid ibaka, a badly overpaid perkins, and jeremy lamb. presti has really botched things pretty badly (though he drafts well), the thunder are good, but there's a decent chance they'll never win it all. maybe they should have used those pieces to put together a more ambitious package for a truly elite player instead, someone would have bitten.
and i wonder if the team was still in seattle if they could have gone further over the cap?