Are certain statistically-good defensive teams more likely to collapse when they play good competition than others? My guess would be yes. My speculation is that teams that rank near the top in eFG% allowed (this season, the Bulls and Celtics) are least likely to collapse against good teams.
I wouldn't be shocked if that was the case, but I'd want to look at some research before I assumed it to be true.
I think the Knicks own offense's propensity for live ball turnovers would be as big of a factor as relying on forcing turnovers. Especially given how Miami is so aggressive in transition, the complete joke of game 1 was fueled by 24 turnovers.
Edit: Also looking at opponents shot locations it appears typically the Knicks get beat from the three point line and the foul line. They do a very respectable job of limiting at the rim shot attempts. (only allowing 24 shots at the rim)
If you want to know the value of Dwight Howard, the Magic allow a league low 21 shots at the rim this year. That's with the not very good perimeter defenders surrounding him.