All good points, and these were all tactics that were indeed used. History has proven their effectiveness over and over again.
But I can appreciate the guys in the video trying to pare down all of the various other factors to one simple question- can a period accurate arrow, fired from a period accurate bow pierce a period accurate breast plate, and the answer is apparently no, which makes sense, as that is what the mail was designed for.
I agree that a long distance hail of arrows would be devastating to an oncoming force (and their horses), and that aiming for weak points would yield different results. Again, all are proven
strategies and strategy is not the point of this experiment.
Although it certainly is fun to discuss!

Def