Having great coaches, feeder systems, and a culture for the sport absolutely matters. But so does enrollment, here's why:
From 1980-2016, unless you can prove me otherwise, Carmel, Ben Davis, Warren Central, North Central, and Penn were the five largest schools in the state. During that time period, state championships in the biggest school division are as follows:
Warren Central (9), Ben Davis (8),Carmel (7), and Penn (5). That's 29 state championships in 37 years. Four of the top five enrollment schools ranked 1, 2, 3, & 4 in number of state titles. You really think there's no correlation between enrollments and championships?
The other eight championships were spread out among six other schools. Center Grove (2), Bloomington South (2), Snider (1), Castle (1), Lawrence Central (1), and Fishers (1).
Still coincidence?
You can't win without a good coach and a good culture, no one is arguing that. The argument is simply this: Large enrollment numbers makes it a hell of a lot easier.