I'm a big fan of Nurkic. BUT, I don't think he would give us anything that Zizic can't give us, and I think we need a center with much better lateral quickness than he has.
Not sure we can pencil in Zizic for 16/11 (what Nurkic averages in starter minutes) the way you could with Nurkic.
On the turnover issue - isn't that one of the more fixable problems someone could have, especially at age 22?
Heck, Terry Rozier is older than Nurkic and his flaws are far more worrisome.
He's also cost-controlled for this year and next.
I think if the price is right (meaning Rozier and a non-lottery draft pick or two), it's a good move. Helps our rotation, carries little long-term cost.