Personally, I find this "unicorn" concept less than appropriate in describing any student athlete at any level of college baseball.
As it got originally brought into this thread, it was the "one" in, what, one thousand D3 kids who could play at any level of D1. Now it appears to have morphed to that HS player who can successfully compete at the top 25 programs and chooses D3.
This is completely unfair to those at the D3 level and those at the D1 level. Far too many of these players are grinding in the classroom, in the weight room and on the baseball diamond. They sacrifice a fair amount but relish the challenges in ways I certainly didn't understand when I was age 18. Summer wood bat leagues provide a very fair playing field to measure D1/D2/D3 and JC along with NAIA. Baseball is very different than football or basketball and 11.7 plays one role in that and less than fully funded plays another role. Academics plays a big role also.
For instance, our son was about 150lbs and a multi-sport guy coming out of HS. He had D1 options (not a lot and certainly not an elite D1 recruit by any means.) With 2 years of college, baseball specific conditioning, and playing baseball year round, he was a D1 player.
He was not a unicorn He was a grinder who made himself, through great college coaching, into a fine baseball player. I don't think our son was too unique except in the fact he ended up at a very high level by using every ounce of talent in his body. Our kids are not unicorns.
I don't like anyone setting the concept of "unicorn" when it truly does not reflect reality and, to me, cheapens the effort it takes to become an awfully talented baseball player.