My first impression of Shamet was terrible - I thought I was looking at Brandon Knight! They are a similar build and size. Of course, Brandon is not a terrible player... wouldn't be if his head was on straight, I should say. Shamet has better floor vision and passes better but the defensive write up him again sounds a lot like Brandon - video showed no D. That was plenty to put me off him entirely. We have to have better than average D in our PG.
I also checked out Jalen Brunson (Villanova) who someone, I thought, heralded as a defender. I watched two videos and was surprised to see he was bad on D - he was constantly getting too far away from his man to recover and contest a shot. So constantly that I wondered if it might be the defensive scheme for some strange reason - he always floated to the middle of the key but did nothing worthwhile there. He never applied pressure - ala Jevon Carter.
If Harrison returns I'd rather give him a shot at PG than either of the two above.
I watched more of Carter - I hate to disagree with AzSteve but I don't see a slow first step. I quite liked his offensive game. I confess a good bit of it was that he ran the old-fashioned give and go play well. He has a good midrange jumper, too. It's out of fashion but if teams are giving it to you, and you can hit it, it's still a good shot. If anything he may be too much of a gunslinger next to Booker but WVa relied on him for a lot of scoring, so there's that. He was slotted at 47 the last mock I looked at so you'd think 31 would safe but, frankly, I'd reach for him at 16 just to be sure.