If the Jazz draft Williams, they ought to start Al Jeff, Favors, Williams, Hayward and Harris, with Millsap and Miles coming off the bench.
If the Jazz draft Barnes, they ought to start Al Jeff, Favors, Barnes, Hayward and Harris, with Millsap and Miles coming off the bench.
So it's a question of whether you want Barnes as a spot-up shooter out on the wing with Hayward, or Williams as a player who can actually wreak havoc, draw double teams and get to the line. Both can play decent defense.
I like both players. Barnes has the better shooting stroke, but I think Williams is the better scorer and will have the bigger impact overall that'll translate to more wins.
There is some redundancy between Williams and Millsap, but I think Williams is the better talent.