So we're sorta on the same page, maybe just reading things with a different tone. Your question, "but at what cost?" hits the nail on the head on this issue. To that specific point it is a balance of how aggressive and/or physical do you get in order to outscore the opponent (which of course is how we win the game) and how do you go about that......some very successful teams/programs adhere to what you are advocating for (MSU-Purdue-Wisconsin-others) really get after it on defense....those might be extremes and (I believe) that is what Seton Hall wants to do, they just weren't able to keep up with Iowa's free wheeling and fast paced offense.
Let me state, I wish we were better defensively and, I have been frustrated with our inability to accomplish that under Fran. That said I think, with no basketball expertise, that the ideal way to play is to play good defense without fouling while being very effective and efficient on offense. I "think" that is what Fran is trying to accomplish and is obviously better at coaching offense. All that goes to my point that the 2 foul rule doesn't cause players to play more passively...it is meant to make them play defense and avoid fouling at the same time.
Let me take that one step further.....that is why I think Fran likes to switch up defenses and will only stick with either man or zone when he feels like his team has the matchups to take advantage of that. This is also obviously predicated on his players......JBO (who in my mind was/is a great Hawkeye) did not give a lot of effort on the defensive end until his last year. He was much better at defense at that point, but still limited based on size and strength....so, when ONE of the five breaks down in Fran's system it REALLY hurts the defense.
We are now in a different era as far as our guard court....we have good size and decent athleticism that should allow for better TEAM defense based on the individual players.