Quote:
Horse head is facing right and tail is facing left.

Coin #5 rotated appears to be from Antioch in Pisidia, with vexillum between two standards on the reverse. Can't make much of the obverse on this one either, but if you can make out any of the legend on the obverse it could help to identify the emperor.
Below is a comparison with a Volusian coin with a similar reverse which is slightly larger in diameter at 23.90 mm, but much heavier at 6.86 gr.

This search string may help:
https://www.acsearch.info/search.ht...currency=usd