They're different players, that's true. AP is primarily a SG who can play some PG minutes. JJ is primarily a PG but can also be effective at the SG in limited minutes.
His toughness and defense, which are apparently two of his biggest attributes, will make the second unit very, very good. To be honest, with:
Jack/Derozan/Wright (one of the two, whoever doesn't start)/Evans/Rasho/Delfino(?)/Pops(?)
I really think we have one of the toughest benches in the league. We're no longer relying on POB, Douby, Ukic, Kapono, and Graham to play a lot of minutes. IMO, this will prove to be the biggest difference between this and last year's squads. Our starting 5 last year was pretty good already, even with an injured JO playing in the beginning. But, we were so thin on the bench, I think my middle school team would have given these guys a tough time.