To get away from the relative accuracy of clubs for a moment (for what it's worth, I agree that shorter shaft/more loft will be more accurate, all other things being equal*), my main aim in setting up my bag is to have a relatively even spread of distances through the bag, irrespective of the number on the bottom of each club. If that means that I'm carrying two irons with the same number on the bottom, or two clubs that have the same loft, I have no problem with that.
*One thing that I would need to see from the 'modern tech' club is that the distance that I get is consistent between shots - to me, I'd have a strong preference for an 8-iron that I hit 125 yards plus or minus a yard or two on a good strike than a 9-iron or PW that goes 125 on average, but gives me the odd 120 or 130 for no obvious difference in swing or strike. Accuracy, to me, is about distance control as well as direction.