Based on Hornacek's history, both as a player and a coach, he seems to be very comfortable having 2 playmaking guards on the floor at the same time.
In Phoenix it seemed as if at least 2 of Dragic/Thomas/Bledsoe, or later Bledsoe/Knight were on the floor together (when healthy) most of the time.
I wouldn't be surprised if he started and finished with Rose/Jennings on the floor, doing some O/D switching with Lee. But presuming both PG's get significant usage (30mpg+), we'd better feel pretty good about our 3rd PG. I reckon Sasha is serviceable, especially if Noah can act as an interior distributor and KP evolves from this standpoint.