Nah, man. He really can't get his shot off against a competent defender. He's good at backing up and driving past defenders, definitely, but there's a limit to what he does at that point. As mentioned above, he's taken fewer shots in the paint than Dillingham has total makes, and Dillingham isn't exactly a great finisher.
Sheppard can absolutely take advantage of a defense that is scrambling and moving around or in transition. What he cannot do is self-create much out of a stand-still. Gravity is what Damian Lillard provides -- drawing multiple defenders to have to handle him. If Sheppard has a competent defender on him, he's not getting his shot off.