Interesting idea to be honest.
Keep Favors. Keep Kanter. Keep Gobert. Bring over Tomic. Don't let getting Embiid change your plans for those guys at all.
Take your time with Embiid. Let him heal. Let him work with NBA strength and conditioning coaches. Let him play limited minutes against backup players and flash some of that incredible potential. Then when teams start looking at making a big deal, all of a sudden Utah is high on the list because they have an asset that is highly desirable. Because there's no way that you'd consider trading a star for little more than the 5th pick in the draft. . . but if Joel Embiid stays healthy for the full season and looks good doing it - well, that's a different story.
Of course, if you trade him and you're wrong. . . that **** hangs over your legacy forever.