i think one of the factor that makes hes calculation wrong is the very agresive OC, the 1070 neoscrypt is 1100 while user in real scenario users will reduce the power limit upto 75-80% making it at 850+ only.

That is around 250 hash in difference which is alot multiply it by your number of cards which is really inaccurate.
Not just 1070 but almost all cards in the calculator have a very agresive OC result.