Aligning broadheads to fletchings is an old wives tail usually spoken about by drunken men and women around the camp fire.
I dont matter one iota and wont make a bit of difference to how your arrow flies.
Just think of this how do you align a 4 blade head or a 2 blade head to your fletchings.
Just make sure your bow is tuned and your arrows are tuned ie spin test them to make sure there is no wobble in either end and are the propper spine for your set up.
Then once you have your bow and arrows all tuned up it is time to tune up the shooter with correct form and follow through.