Like whom?
If you look at DBPM for that Little rookie year, his DBPM was worse than Hezonja or even Hood's very injured shell. Gabriel, fwiw, was also behind Herzonja in his DBPM.
What defensive tools did Terry has that he did not play? The only players with a positive DBPM that year were Nurkic, Whiteside, Bazemore, Ariza, Herzonja and Skal. That's it. There were no defensive options on that roster. Zach Collins was not back to his defensive standard after the injury, that team had no defensive players on the roster that did not play. It was a crap roster, simple as that.
BTW, for the very small sample we have seen so far, it seems like ZCo is finally back to being a defensive force after all these injuries. Still a minus on offense, but on defense, he is starting to look again like his old self.