OK people on
ebay are writing to me and the premise of who made the radiate countermark might be flawed because as the person writes to me, the: "countermark on this type is generally unclear and described as uncertain, though it has been described by CNG as a lion head (what you see as rays being the animal's mane) as seen on a related coin. It seems unlikely to show a radiately crowned human head (seldom used on such old coins of Greece or western Asia Minor).
So I guess forget the question and perhaps Romans never countermarked old Greek coins anyway.