From what I’ve seen, at the very top LACs (US News top 5, for example), at least in the mainstream mens’ sports, there are very few walk ons. They are almost all recruited. I’d say at least 95% are recruited, on the teams I’m aware of, it’s 100%.
That being said, at those schools the majority of those recruited athletes have GPAs and SAT/ACT at or above the school average.
It’s fairly remarkable - to have such high numbers and great athletics - but they do manage to get those kids.