Adams switches between several claims (which are not incompatible). One claim is that Clinton often screws up, while Trump virtually never does. Maybe Trump only uses basic techniques, but if Clinton and the well-funded primary opponents fail to use even the basics, that's an interesting fact about the world. And by screwing up, he doesn't mean failing to engineer statements, but own-goals. Another claim is that Trump's techniques are more advanced than Adams's own techniques, but he can't communicate the difference to people who don't already have a solid grounding (so he doesn't try). Adams is good enough to recognize the greatness but not produce it. And Trump tests lines at his rallies to get even better results. A third claim is that Trump is good on his feet (Adams always gives the example of the Rosie O'Donnell response). Maybe Clinton can hire someone to write killer tweets, but she'll be outmatched at the debates.

I don't mean to endorse any of these claims, but they seem like reasonable possibilities and what the world would look like under his general claim.