Fans do tend to value their team's players more than other GMs do. I don't have a dog in this hunt, so take it for what it's worth. I really don't see OKC with a big 3 comparable to Miami's plus a 22year old Ibaka putting up a near double-double every night and leading the league in blocked shots feeling a desperate need for LMA at the price you suggest. They're almost certain to have the #1 seed in the West, they're healthy and talented and deep. They are my favorite to win it all, and they look like they could repeat. And threepeat.
Oh come on now. Serge Ibaka's "double-double" every night is actually 9 points and 7 rebounds, with an 18.5 PER.
OKC's biggest problem, and I believe it will be their downfall in the playoffs, is that they have no inside post scoring options. As games slow down in the playoffs, points are harder to come by, and if you aren't hitting outside shots, your offense stagnates, or your PG starts to dominate the ball.
That's what Westbrook did last year against Dallas, and frankly, I don't see how they've improved their ability to get points in the paint, and to get the opposing bigs in foul trouble.
Also, not trading James Harden for LMA straight up, even in fantasy land, is just so ridiculously hilarious that I have to assume you're just stirring the pot. Yes, let's not trade for a legitimate post scorer, in the prime of his career, and on a very nice contract, because we need to keep our 6th man, who will likely be seeking starter-level money, and maybe even an expanded role in an offense, after his rookie deal expires.