Lol, did Nephew show those hesi moves, flash the Euro steps, all in his rookie season? Easy to look at his 30-year-old game and see how comparatively lackluster Primo's looks. But it's a serious misconception thinking he came into the league with those things solidly "in his bag". He learned all of that in subsequent off-seasons (one of the only players who truly brought something new into his game every season) of training and hard work, the same way Primo can.
I'd actually say Primo's shown better "moves", specially on isolation, than Neph did in his rookie season. For example, I've definitely seen Primo euro-stepping in one of his earlier games, not to mention those pullup-3 moves he used to pull out, but stopped once his shot got wonky. Of course, they're completely different players and Neph had a lot of other valuable aspects to his game - I'm strictly arguing against this notion that Kawhi was a polished, or creative/natural, offensive player in his rookie season.