The next turn after this, he lost the Polypotes trait and got it replaced by "Sober" which was more in line with his other drinking trait, and stayed that way for 3-4 turns.

The reason that the argyraspidai, and Euphrantos there, have experience up into the silver chevrons is because I had them sitting in Pella weathering countless assaults from the Epeirotes (thus making Euphrantos "Grizzled" by the time this image was taken). Since I can make argyraspidai at Pella, I just kept retraining those three units, never made any more that those, and the assaults just kept coming and coming.

After Euphrantos beat off that Epeirote army that is seiging his city in the image, the Epeirotes ran out of troops for a few turns, giving me a bit of a breather.