back on the subject of smaller and lighter arrows, a stack of 5 arrows should be roughly the same as the size of a shortsword, weight though would be determine by the material the arrow is made of. consider, when other types of arrows are implemented aside from just the iron arrow, that all arrows have wooden shafts, the most basic arrow would be just a sharpened stick, those would also be the lightest, say 0.2 weight, now when you get into arrowheads, those should really only marginally affect the weight of the arrow, an iron/bronze/gold/etc tipped arrow would probably be 0.3-0.4 weight, if we get into stone or gem tips (someone mentioned diamond tips) then maybe between 0.2-0.3 weight.
with those numbers if you take 5 stacks of 65 bronze tipped arrows that weight 0.4 each then you're carrying around 130 weight worth of arrows which for those with max strength and no buffs is nearly half of what they can carry as is.
as for recovering arrows from corpses, the realistic way of handling it is to add a fletchers skill for making arrows. when you shoot arrows the arrowheads should have of chance of being recovered but the shafts should become useless, so people can take the arrowheads they collect, get some new shafts and reuse the arrowheads that way.