I'm fine with the Grayson pick. After the Wizards took Brown I knew the Jazz were ****ed. I thought Brown or Huerter would go to Atlanta and the Jazz would take who dropped. At that point I thought there was only one high potential player left, Okobo. I'm disappointed we didnt go Okobo, but I think I know why they didnt.
I think they want to keep the relationship with Exum as positive as possible going into contract negotiations. If the Jazz draft another player who labels himself as a PG, maybe that turns Exum off from negotiating in good faith. If Exum signs with the Jazz long-term, there is still a clear path for him to be a starter in 2019/202 if he plays well enough (to be clear, I dont think this is likely, but I think it's important for Exum to think it is). When Allen got drafted all he has said is about how he is excited to play off ball more, which was probably a selling point for Utah since they have 3 rotation guards who are better on ball than off already. I know some people will roll their eyes at the thought of that, but I still think Utah believes in Exum (who is only a few months older than Allen).
If they took Okobo, it would be another player who needs to be on-ball to develop to his true potential. Not that Okobo is useless off-ball, but his biggest strength is off the dribble shooting and PNR. With Allen he has a bit more offensive versatility and a larger body of work to prove he is a good shooter. I bet they also believe in Allen's defense a bit more. They both showed similar issues defensively in PNR play, but Allen shows more fire in other areas which probably gives them hope he can translate that into playing more focused/high energy in a smaller role/minutes load on the defensive end.
As well, the Jazz's peak competitive years should start in Year 3 of Donovan's career (of this current iteration of the Jazz). By that time, Grayson Allen should essentially be in his prime (or close to it), so he fits in nicely with Utah's timeline as a discount Eric Gordon/6th man type.