Hayward is ... a two-way player, a good shooter/passer, rebounds solidly, has prototypical size, and can playmake a little.
I think that you've both underestimated and overestimated him here.
Two-way player? Not really, but he's adequate/average on defense.
Good shooter/passer? I'd say outstanding/very good.
Rebounds solidly? Nothing special.
Prototypical size? In some ways better: 7-foot wingspan.
Can playmake a little? Here I think you are drastically underestimating him. He's very good, and does it with an extremely low turnover rate. Combine that with his ultra-efficient scoring, and he's someone you want to give the ball to; he makes his teammates better.
Maybe he's not going to be the primary option on a great team, but he can certainly be the 2nd one. He doesn't have any obvious flaws, he just doesn't happen to be a full-time SG or PF.
Since we've apparently entered the world of ball-handlers/wings/swings and bigs, the need for a full-time SG or PF does not appear to be urgent; in fact Avery Bradley, who does not have good position versatility, became a casualty of the revamped roster.
As for primary and secondary options, again I think that you are underestimating Gordon, since so many good things happen when he's got the ball. But the reality in the NBA in 2017 is that the hierarchy of "options" is less relevant than it ever has been, the value of ball and man movement being now at its peak in the history of the pro game.