OK.
Let me get this right: to show some archers how ancient arrows were hafted, he got these things-- from a museum ? from his own collection ?— and hafted them ? On the grounds that "we've got lots more" (not thousands; even the dig at Olynthos did not yield thousands of arrows and sling bullets; nor are battlefields excavated on a regular basis; and they do not yield thousands of arrowheads; and they wouldn't quite look like those-- more usual would be trilobal small points, and big bronze hooked Cretan ones)
The question still remains: where were these found ? If a recent dig, I wonder why they're in the US and not in Greece (I thought that removing any artifacts, especially from digs, was forbidden by law). Could be one of the older American-run digs-- but which one ?
And a new question: who is your friend ? Just curious.
To put it differently: the arrowheads look a bit odd, the explanation ("Thousands of these things !") is so cavalier, the treatment of actual artifacts so blunt, that I thought this was an amateur archaeologist flaunting his illegally acquired antiquities, a subject about which I feel strongly because it depletes a finite resource, the material remains from the past; on this subject, see my favorite blog
http://paul-barford.blogspot.com/--which is why I assumed what I did. There was no insult meant; but probing questions, yes.