I agree with your point, but it's not as easy as it sounds for a school like ISU which is surrounded by farmland to attract 3-4 legit B12 bigmen at any one time.
Look at the proximity to talent for those schools, and/or how attractive their locations are for recruits.
Oregon has 7 kids from CA/OR/WA plus the rest of the benefits of Oregon speak for themselves.
UNC probably doesn't need much of an explanation but they have 13 kids out of 15 on their roster (not sure which are walkons, etc) that are from the Eastern seaboard.
South Carolina has 4 kids from their state, and their two best players are from SC.... Thornwell and Dozier.
Gonzaga recruits a little more nationally but they're now one of the top options on the West Coast along with Arizona, Oregon and UCLA.
It sure would be helpful if ISU had an occasional 4* bigman that was from our home state.
I think part of our "small ball" strategy has simply been we've had a hard time landing more than 1-2 B12 caliber bigs on any given roster.
When 5 of your top 7 players are guards, you play small ball.