Just about the Medieval arrows... Generally the arrows used in medieval times would have required a very large (say 7" minimum) fletching, as the arrow heads were so heavy, without the large fletchings the arrows would fishtail badly. I think there can probably be a lot of debate about the height of the fletchings as AFAIK there isn't much evidence as to how high the fletchings are, however there is evidence as to the length. The fletchings on my arrows vary from 1/2" high to 3/4" high at the trailing edge.
However I'm sure there are exceptions, and probably quite a few of them!
The English warbow site and forum is a great place to find out things about medieval archery.