He says we have depth at those positions, he didn't say anything about an upgrade though.
Right.
Think about the roster in terms of his "ballhandlers, wings, swings, and bigs" categories:
BH - Thomas, Turner, Rozier, Pressey
W - Smart, Bradley, Young, Hunter
S - Crowder, [Jerebko], [Datome]
B - Sullinger, Olynyk, Zeller, Mickey, [Bass]
You can see that the category which is thinnest right now is "Swing," and the team already has 4 bigs on the roster.
That said, the "big" category is 4 deep in guys who are probably bench guys on a good team. The "Wing" category is also pretty undersized.