When looking at Kyle Lewis and the "level of competition" concerns with him, I go back to Kris Bryant. The guy came out of a similar small conference team. His strike out rate as a junior was around 15%. He hit a home run every 7.2 ABs. Kyle's is around 15% and hits a home run every 10.9 ABs.
Even if there is some swing and miss in his swing, you have a guy who is legitimately a 30+ home run potential power bat with the ability to stick in right field. He projects to be what Jason Heyward should have been.
I really like the Lewis and Bryant comparisons, and they do seem to be performing much the same against similar competition:
Lewis - .425/.554/.774 1.328 OPS, .71 K/BB
Bryant - .329/.493/.820 1.313 OPS, .67 K/BB
Bryant had a higher ISO (.491 vs .349), while Lewis hits a lot more singles.
Bryant was also a stud from the moment he stepped foot onto campus in San Diego (OPS of 1.081 and 1.154 his first 2 season), while Lewis has grown by leaps and bounds (OPS of .722 and 1.100 his first 2 seasons). I would expect that from a kid who didn't play baseball full time until he was a senior in high school though.
Bryant put up a very pedestrian .223/.304/.369 line in the Cape in ~150 PAs after his freshman season. After his spohomore season he was tabbed for the USA team, but I think they eleminated baseball from the olypmics so he didn't play any game.
Lewis played in the Great Lakes League (no idea how good that is) and put up a .342/.425/.533 line in ~185 PAs, as well as 8 PAs in the Cape (meaningless sample) after his freshman season. After his sophomore season he had ~160 PAs in the Cape and put up a .300/.344/.500 line.
The fact Lewis plays CF and is projected at having an outside shot at sticking there as a pro tells me he is a little more athletic than Bryant, but I don't think it's much of an advantage.
I wish I could find split data for Ray since it's the main concern I have with him. It would be pretty bad to select a platoon OFer with the 3rd pick of the draft.