The top of the draft will change. Right now, the top 3 we assume is Okafor, Townes, and Mudiay in some order, but last year we assumed it would be Wiggins, Randle, and Parker in some order. Then Embiid came out of nowhere.
I agree, though, that the chances of us making the trade up are not good. The other teams up there are going to be the tankers, and they want the maximum upside just as much as we do.