I don't know about arrows,But Gravity is clear,if you drop a boulder off a cliff at the same time you drop a tiny pebble,they both hit the bottom at the same time,now on the other hand,if you drop the boulder and a feather the feather will catch the air and fall at a slower rate,

So I would be more prone to believe that a lighter weight arrow with feathers would drop slower than a heaver arrow with veins or maybe even a heavier one with feathers,

I would just be more prone to believe that the light weight with feathers would catch more air,and veins would have more presser pushing them down.