a cautionary comment ...
a "modern" 2-fletch DOES work well, IF all the right parameters are involved - the shooter's form/release is good and consistent, good bare shaft flight under hunting conditions, and the 2-fletch arrows have been well field tested under hunting venue conditions.
the reason(s) for using a 2-fletch? i don't see any that are major functional, and i don't buy into the added quietness. i did my own 2, 3, 4, 6 fletch testing and feather noise has much to do with the feather fletch itself, the degree of offset/helical, the shape and height, AND your release. i mostly use a 4" banana low profile 4-fletch and it offers as little a 20 yard downrange noise as 2 and 3 fletched arrows of varying shapes and configs.
the reasons for more than 2 fletches can be summed up in one word - "insurance". faster arrow spin, quicker paradox recovery, added arrow stability.
there are bowhunters who should not even attempt a 2-fletch 'til they get all their ducks in a row, first. and even so, yer adding another measure of concern when out hunting.
this is NOT to knock those who know how to use a 2-fletch - just as with those who prefer to go trad primitive, it's all viable trad bowhunting if in the right, capable hands.
and that's that, from my perspective.