Well if I can jump in here I'd start by saying that I don't think you can go wrong with either player. I think their close talent wise at this moment. As to projecting the future, that's harder to do with the one and done player. There's no growth record to go on. But in the case of both Agbaji and Mathurin, we do have some growth records to refer to. And in both cases, both players got better every year. Particularly Agbaji, who increased his percentages as his attempts went up. His freshman year he shot 30.7% from three on 3.4 attempts. His sophomore year he shot 33.8% on 4.4 attempts. Junior year 37.7% on 6.9 attempts, and his senior year 40.7% on 6.5 attempts. That's the kind of growth your looking for., It shows he capable of getting better, and that he's willing to put in the work.
In Mathurin's case we only have two years to look at. In his case, his percentages went down with more volume, but that's the norm. But his overall scoring went up and didn't take a huge nose dive. He was still good. His freshman year he shot 41.8% from three on 3.5 attempts. His Sophomore year he shot right at 37% from three on 6.1 attempts. He scored around 8 more points a game. Point is, he got better. Both players are above average athletes and both players are good defenders. As I said, I don't think you can go wrong with either one, but for the Kings. I would lean toward Mathurin. Mathurin can play SF. He's a legit 6'7" and the Kings need help at that position. Agbaji is a pure SG. He does have good length and could spot at the SF position at times. but so can Terrance Davis.
My choice for the Kings is still Keegan Murray, but I don't know if he'll be there when we pick. Murray is a plus defender. Matter of fact he as a better defensive rating than almost all the projected lottery picks. By the way since there was some questions about Jabari Smiths defensive potential, he held everyone he defended to a shooting percentage average of 25%. That should be good enough for everyone.