Dowling is plenty good, and is rated by Max Preps at 245th in USA. That's pretty good in my book. And they have certainly proven they are a large fish here in Iowa 4A. But, I suspect in the Chicago Catholic League, competing against Loyola Academy and Brother Rice, et al, they might be regarded as fairly average in that pond. If they were to "play up" against the upper eschelon of Chicagoland (and other larger cities) public schools, Lord have mercy. Dowling might win a game here or there, but would most likely find it difficult to compete week in and week out against those big boys. And, I'm very certain the supporters of top programs around the country in 5A/6A/7A/8A would ardently shout down any little ol' Iowa 4A squeaking about their quality.
Can a really good 3A team compete in 4A? Sure they could. Contend for the title? Maybe occasionally, but mostly not...shades of gray, on a given day, when the moon is just right, maybe. One thing is for sure, the mere speculation sure makes for a lot of bluster and prideful clamor on both sides, doesn't it?