They should share the blame, of course. But it won't affect their draft stock.
Wiggins hasn't learned to deal with all the attention on offense. When he gets the ball, he sometimes has one man trying to force him left into two help defenders. It leaves a jumpshot as his only shot, which isn't his strength yet, and while he's unselfish I don't think he has the court vision (yet?) to hit teammates left open by the overhelping defense. If he could pass well enough to beat the overplay, then they couldn't do it as freely and he'd have more room to work.
And I agree, Self isn't helping things because it should be pretty easy to tailor an offense around the massive attention Wiggins gets - or just get them in transition and let Wiggins be the best athlete in college basketball. Either one would work.
Embiid's problem is easy - he can't stay on the court. 3.5 fouls in 21 minutes per game (to wit; forgive me if I'm a little off, going on memory here). You obviously want him on the court a lot more.
Now, in a sense I don't think those fouls are necessarily a bad thing. Young, raw bigs trying to play defense foul a lot - that's just how it is. Takes them a long time to learn how to impact the game defensively without fouling. If they aren't fouling, chances are good that they aren't playing much defense. So here you have a young big man new to the game who is trying to be the dominant two-way player he has the potential to be, and while the effort is there the experience hasn't caught up with him yet. Again, not a bad thing as far as Embiid's future is concerned - it's just a matter of time in my opinion.
Just some thoughts. I think both players still go in the top 3, and each has a reasonable argument to going first overall even.