I love how the double strike on the obverse of the OP coin gives the horse and rider a motion blur that actually looks intentional. I would have bought that coin because of the double strike.
The latest addition to my dolphin-rider pod arrived earlier this week, courtesy of Frank Robinson's most recent auction. I was saving one or two slots of my allowed twelve for an earlier nomos of Tarentum. In place of the horseman, this one has a hippocamp. #5 CALABRIA, Tarentum AR Nomos. 7.86g, 19.3mm. CALABRIA, Tarentum, circa 500-490 BC. Vlasto 115. O: Phalanthos riding dolphin right, holding cuttle-fish in right hand, left hand extended; TAPAΣ (retrograde) below. R: Hippocamp left; scallop below, TAPAΣ (retrograde) above. Ex Pegasi Numismatics XXXIV (24 May 2016), lot 18