Yes foreign athletes on scholarship is high. I wouldn't travel to USA from....Kenya, or Slovakia and hope to get a ride. I would stay local and hope to get recruit call from overseas. That is what happens.
But clearly the majority of the scholarship money is doled out to USA student athletes.
No argument that USA colleges train a lot of foreign superstars however the trend in recent years is the best foreign athletes (Jamaica,Norway,France, UK,Germany) stay local and prosper, exception Kenya (and their medal tally has dropped over last few WC and OLY).