Well that situation is really the only time i look to post up - when the defenders rotate over because of a pick, and my 6"7 SF has s height and strength mismatch over the smaller SG/PG. My ball handling/security/post-offense is maxed out so just because a PG has a high steal attribute and pick pocket sig move I shouldnt be getting the ball tipped away every time when i post up. My height, weight and strength advantage coupled with my attributes should be more than enough to successfully back down a smaller opponent.
I never feel the need to post up on the opposition forwards because my slashing SF with a speed of 90 can usually beat them off the dribble, cutting through the lane or work the P&R. Maybe i should just post up on the forwards anyway.