If Turner Truly doesn't want to sign an extension with the Pacers, it'd be in the Pacers best interest to trade him before he walks for nothing. Poeltl is a defensive monster and a monster in the post and lob threat. He would fit in nicely and likely take the pay day to stick with this young team on the verge of competing.
Spurs currently have a 12.5% chance at Wemby while 3 other teams have a 14% chance. With this trade they can boost their odds while getting valuable Lakers 1sts to use when their ready to contend In a couple more years.
Lakers spend alot but a front court of Bron, AD, and Turner would be amazing. And Josh would fit right in at the 2 of the starting 5. And since LAL would get Turner's and Josh's bird rights they can re-sign them in the off season if the group turns out well.