Each comparison is broken down into a per-minute number and then a ratio is calculated. If Biyombo's per-minute number is as good as the comparison player, the number is ≥ 1 and the box is green. If not, the box is red.
I found stats from 3 different teams for Biyombo: CB Illescas Urban CLM, Illescas, and Fuenlabrada. I don't know enough about Spanish basketball to know the difference between the first two teams (or even if they are different teams), but I do know that Fuenlabrada is the top level of the Spanish League, and like it's been said, they would dominate any team in the NCAA (so look at these numbers with that in mind––especially Kenneth Faried's).
The top table is all of Biyombo's game stats that I could find, so you can look through them and see his progression throughout his career.
Looking at these numbers with the level of competition in mind, it's probably safe to conclude that Biyombo would have been a shot-blocking nightmare in the NCAA. He also would have likely been one of top rebounders in the country.
Here is the table: RIGHT HERE!!!