What did you mean by saying that we don't need much fold equity? It is clear that we don't have so much FE that we could get autoprofit -> we need some equity too, and it is also clear that we don't have that.
If you shove QQ, and UTG 4bets AK, QQ+, you have around 40% equity vs that range. With bluff hands such as e.g. A5s you would have vs such range around 45% FE (some standard calculation for 5bet bluffs), but with having 40% equity it is obviously less than 45% FE, don't want to calculate now, but it is likely around 25-30% required FE. Well, I see quite often 4bet bluffs from nits, not saying that they are in general super agro, but my point is, they have bluff range (most of them).