Actually i use 4 blade muzzys and you can still line up your blades with the veins/fletchings but youll alwys have one stray blade either at the top or bottom depending on how your shooting.
ORIGINAL: HuntinGUS
I always did it b/c I was told that I should. I always bought 3 blade heads just so I could line them up.
I am considering going to a 4 blade this year, so lining them up will no longer be an option.