I guess the question is what of the 3 ingredients actually lowers estrogen? We know Arimistane doesn't do much, NAC is a good antioxidant, and Cholorophytum Borivilanium is an aphrodisiac.
So...I probably would keep an actual AI around.
If you are running Nolva, look into Calcium D Glucarate, which has shown to be as effective for managing e2.