Pip Radish, you missed my post of "09 Aug 08 - 07:08 PM." In it, I pointed out three points of connection, not one.

1) 1308, Winchester Catherdal: a figure who has both a foliate head and a sword and shield, and is thus both a foliate head and a combatant green man, is carved on a choir stall. See this not so good picture.

2) ca. 1450: a combatant green man on a German engraving carries a shield in the shape of a foliate head. I have seen this image but can't provide it (it's in the original journal article, but not the freely available online version).

3) 1534: Bench-end (link is above).

That gives you a two-hundred-twenty-odd year span.