It doesn't seem unreasonable that 3,000 could have watched one game and 4,000 could have watched the other, plus maybe another 1,000 who stayed for both. You'd never have a crowd that was much over half full, but the number of tickets sold would suggest otherwise.
Unless the organizers think the majority of fans are going to stay for six hours and watch both games, this would seem to be another argument in favor of moving at least the first round to a home campus. You could probably draw at least 6,000 at most of the universities. I don't know what the population of, say, Schenectady is like, so maybe this wouldn't help in every case, but it's probably worth a look.