I've always liked these coins... http://archaeologynewsnetwork.blogspot.com/2015/01/twenty-five-century-old-mystery.html
A friend on Facebook says there is an error in that article but hasn't said what it is yet. He's letting people guess at it.
Maybe I'm just not very bright like my Momma always said, but, after reading the article, I'm not sure what mystery they "uncovered".
I can't recall an article that said less and said it more poorly. Obviously someone is paid by the word.
http://www.forumancientcoins.com/board/index.php?topic=85622.0 You can read the above which says way too much. A lot of what is said by anyone on these coins is based on theories more conjectural than factual. The first post refers to papers on acadamia.com which are now bad links. Linking Pythagoras to the issue is very important to some while others are equally devoted to proving the coins predate his arrival in the area. Dating these coins is not absolute. I do not have one of the earliest series with spread fabric but I do have a late Kroton stater which only partly captures the idea. My favorite is the little Metapontum 1/12 stater which replaces the incuse of the entire ear of barley with a single kernel.
To me, the answer to the "mystery" of incuse designs is blatantly obvious: metal flow. The anvil die had incuse devices that needed to be filled with metal, so the hammer die was engraved in relief to push the metal into the lower die. Perhaps the minters of these coins had a problem with low striking pressure (for whatever reason), and that was one of the solutions.