Sandals

[hoplite14gr]

Xenophon writes at one point that it got so cold at night men's sandals froze to their feet. I'm sure there are other references to footwear in the Classics - I think there's a reference to 'Persian slippers' in Lysistrata, but that's female attire. However, I wouldn't be surprised if some Greek soldiers did go into battle barefoot. They were used to walking barefoot doing fieldwork.

I think you are right. Also it is hard to imagine troops from the Krimean colonies or Stavropolis (Modern Stavropol) campaigning barefoot there.
Snow there has atendency to stay in these regions until April. Fotware of the Sktythian type might have been quite normal.