The figures have been placed by the Welsh Gov't, as part of a scheme to encourage historical Welsh-ness.This morning I spoke with a Mr. Morgan at CADW .He said it was most likely that the figures of the archers was probably to remind people that the majority of the archers at the Battle of Agincourt,1415AD, were infact Welsh and this year is the 600th anniversary of that great English victory.
see http://www.castlewales.com/trecastl.html