Back to the OP. Unless you bias the fitting process by saying you want only this certain iron. You could see 10 fitters and see 10 different outcomes in terms of the head they choose for you.
Even taking it further. You could see 10 different fitters and say you only want to try 1 head you could end up with 10 different results. Whether it be Different shafts, different lies, different lengths, different grip choice, different grip size, loft adjustments you name it.
if there was a universal truth or ultimate combo why then do fitters go get fit. They of anyone should know their ultimate combo.