Figure 14, on the page marked 76 in the lower right, is a timeline. The left hand
column shows centuries BC - 9th to 3rd.
One needs to be a real expert to date arrow heads but it appears that the ones used in the 4th-3rd c BC - thus the time of Phillip and
Alexander -
had no socket protruding down below the back of the wings.
But my main point is not to assign a specific date to your arrowheads - the chart seems to indicate they date more to 6th - 5th c BC but I am no expert - but to show that one thing we can be certain of is that they were not "designed by Philip and
Alexander".
Shawn