There's interesting thing about it. What's basically this thing "create his own shot" which supposedly distinguish “star player” from “role-player”? Good role player on offensive end should be able to do some (if he's great role-player - all) of following: exploit mismatches by driving through slower defenders and posting-up smaller ones, spread the floor by knocking down open 3s, run the floor in fast breaks, cut for easy baskets., move the ball (some assists would be nice), go for offensive rebounds ... And yes, Casspi can do all those things good or at least reasonable well.
What role player is not supposed to do (and Casspi actually avoids doing it) - is trying to beat opponent one on one when there's no clear advantage established... Why should the stars resolve to do it? First. Some of those guys are unbelievable effective. Lebron, Durant and Steph Curry are doing this a lot and still their career effFG% are 53.3%, 53.2% and crazy 57.5% for Steph. Then. It could be because team offense is stagnant, not effective and better opportunities couldn't be produced... (also some "stars" "going ISO" just because they think it's "what stars do")
Now Rudy Gay career effFG% of 48.6% is not terrible ... but it's not really great ether. So maybe "creating" some middle-range shot is not that great idea in his case.
Now another thing. It seems to be quite reasonable that role-players would be effective scorers - as they can select good shot while stars are obliged to take all kinds of shots... The reality that almost all of role-players are actually not effective scorers - or because they don't understand what's good shot (hint: long 2pt shot usually is not the good one) or because they just can't get or hit good shots.
And when speaking about Casspi. The last year official list of 10 most effective scorers (by effFG%) is as following:
1.
DeAndre Jordan • LAC.703
2.
Stephen Curry • GSW.630
3.
Dwight Howard • HOU.620
4.
Hassan Whiteside • MIA.606
5.
J.J. Redick • LAC.593
6.
Enes Kanter • OKC.583
7.
Kevin Durant • OKC.573
8.
Chandler Parsons • DAL.571
9.
Klay Thompson • GSW.569
10.
Marcin Gortat • WAS.567
As you can see - or big man scoring mostly on dunks and short-range shots over opponents (DeAndre, Howard, Whiteside, Kanter, Gortat). or star players (Curry, Durant, Thompson, Parsons) and one very succesfull 3pt specialist (Redick).
To get to this list player had to make 300 baskets in the season. Casspi had ... 299. And his effFg% was .571
I would say it means that Casspi is quite special multifaceted player which is not star... but can be 6th man or starter (yes, when there is couple of stars in the line-up)