Lowry points per shot... 1.19
Trey Burke PPS... .97 (last among qualified point guards)
Dante Exum PPS... .94 (the same as JLIII)
Lowry's defense is much better than Burke's and at least on par with Exum's current defense (Exum has much more potential obviously).
Patterson is an upgrade over Booker. I love Trevor and his leadership and one liners, but Patterson is a better player and fills that stretch big role.
If the cost is the 12th pick in the draft go ahead and look over the this list....
https://www.mynbadraft.com/nba-draft-picks/12th-overall/120509/
In the last 20 years you've had a handful of rotation players, a couple ok starters, and a **** ton of busts. I think we'd be stupid not to do this trade assuming DL understands Lowry's potential personality issues well.