The difference is Noel was playing for a bigger contract and he probably knew whatever he did he wasn't starting over Adams or eating his minutes, so he hunted for easy blocks and steals to. If he didn't it would be financially negligent. When Adams was injured and Noel was the starter he averaged >30 minutes. Even when he was a starter before Embiid, he averaged 30+ MPG. All this suggests he does know how to stay on the court.
Watching Mitch last season looked like he was just following his instincts for good or for bad.