We are always encouraged to specialise in numismatic collection and study. That can, however, lead to a blinkered approach in interpretation, albeit unintentional.
I will cite one particular example, the silver quarter staters of the Durotriges known as the “geometric type” (Mack 319, Van Ardsell 1242/29, Spink 368). An earlier similar type of quarter stater is also known in gold.
All these interpretations are, I believe, incorrect. I believe that the type derives from the Macedonian tetradrachm and drachms of Alexander the Great and his successors with Alexander in the scalp of the Nemean lion on the obverse and Zeus seated on the reverse.
A series of imitations of the type, of somewhat crude design, are known from Himyarites in Arabia Felix in the 1st century BC. Rotating the Spink illustration of the Durotriges coin 45 degrees anticlockwise gives you the lion's scalp the other feature form the prominent facial features, forehead, ear and/or chin etc. Rotating the reverse zigzag and you get the impression of the seated Zeus, to the right or left, even though on the Macedonian prototype it is always to the left.
Given that the Macedonian Apollo stater of Philip II was copied and degenerated in its westward progression there can be little doubt that the Herakles tetradrachm and drachm was also copied westwards and that its progression should stop in the Balkans with the Danubian Celts.
Danubian Celts tetradrachm