We talked about this on our podcast last night, but because this draft is so weak, the margin between a guard being BPA and a non guard could be razer thin. Nobody is projecting to be a player of CP3s caliber in this class.
But again, as you said, "with Scoot's play," presumably meaning how he's played to date...but the question was asked based on the notion of Scoot's play improving to be at least in the range of the other 3 guards. That is to say, it's not about which are currently the best 3 of those 4, but which 3 provide the best combination of size, skillset, and future expectations if they're all competent, starter-quality players.
My response was in the context of going forward for games, but yes right now, as in Saturdays game and so on. I'm not solely looking at Scoot prior performance, but it is the largest factor in projecting his immediate future contributions. If your talking next season or years from now yeah the response could change. Right now the other 3 clearly help a team win more than Scoot. I don't see any scenario where it's currently beneficial to give Scoot minutes or starts above Ant or Sharpe right now though. It's both bad for the team now and it's bad for Scoots future development. Scoot has been much better off the bench and I think he should stay there for the time being. Brogdon being an older shorter term player is more debatable vs Scoot for the primary backup role.
Additionally I don't understand these qualifications, these players aren't all competent starters right now so how do I grade one above the other for abilities some of them do not yet posses? It's like saying who is going to be the better MVP in 6 years if they both win the award.