So far (all of 4 games into SL), it looks like we neither dodged a bullet nor took one. Fultz looks great and so does Tatum. The Sixers have very scary potential with Embiid, Simmons and Fultz. All 3 COULD be better (potentially) than any current Celtic. If they all achieve... watch out for Philly. Saric also has game and Okafor has skills. That irritant JJ Reddick will hit a lot of shots for them this year. I think Sixers are easily a playoff team if healthy.
For now, Tatum is more of what the Dr. ordered for the Cs than I think Fultz would have been (probably would be singing a different tune if we'd picked Fultz). Tatum's readiness just seems to be in evidence, most importantly his ability to create his own space and hit mid-range shots - and rebound. Of course, both Fultz and JT are untested against the real NBA so time will tell.