They are not really the same. Garnett and Dirk have reliable go to moves in the post, yes they take jump shots more than average and they may not be Duncan but they are still the best post scorers because they have all-star skills to operate down low.
Odom is different because his job with the Lakers is to cut and space out. We don't give him the ball in post and expect something good is going to happen. Lebron does not even have a midrange game. It takes more than getting the ball and driving the ball to be able to be productive on that spot because he does not have the luxury of head speed to create on offense. Just a simple drop step jump shot will do wonders for Lebron but he does not have that. If Lebron ends up retreating to the wing even if he is tagged at the 4 spot, Kobe will just shade him on D and the Lakers zone does its job again.
He will do better on the defensive side guarding Odom though, but then you will get blown out if you think West can make it hard for Kobe.
Right now your best shot is to trade Wallace and get Amare or JO.
I agree Lebron needs to work on the midrange game. But Dirk does not have a post move, he always gets the ball at the free throw line and either shoots a jumper or passes. I have not seen Garnets post moves either, he shoots mostly 18 ft jumpers. He may occasionally catch it closer and shoot a short shot, but I don't think he has all that great of post moves.
Just because he would be our PF, doesn't mean on offense he can't move around. Lebron does have one of the higher shooting percentages in the key, so getting him the ball there more sounds like a good plan to me. And on defense we need him guarding bigs and crushing the boards. If he played down low I think he would be top 3 in both rebounds and blocks.
If Lebron is going to shoot 20 shots and be totally off, I don't think it matters who we would trade for. Lebron had very few shots in the 1st half and we were rolling, then 2nd half, Lebron has to win the game in his mind...