Military hammerdwarf dropped his only equipped sock and going to get new ones from clothier's shop. Gets only one sock. Tons of available socks lying around the fort. Hammerdwarf squad been stationed about one dwarf week. I had just fixed the boot problem, so unfortunately I have no previous save with the hassle with high boots going on.

A quick test after getting them equip both boots did make them to equip boots correctly afterwards when I switched the hammer squad to weapon only (replace clothing, aka naked) and then to the full armour set (replace clothing, use for squad), (This is why they all have both boots and are still lacking some other parts of the gear in addition of the left sock. I might not have enough robes etc. available) I didn't try with disbanding/inactivating again just yet, or with switching to an armor set with "over clothing" option and then back.

I think the problem is that they go for one sock/boot at a time, and so if other dwarf is getting the other half, he somehow refuses to get any other one than the one the other one got equipped, even if a new one with same quality would be available. On socks this isn't so bad, but when they drop their boots, and other dwarf snatches it because it was better quality, they then refuse to go and get new same quality boot no matter how many you'd make. I also noticed that uniform states "steel high boots" and "steel chain leggins" they sometimes did equip some silly elven gear or leather items, even when "replace clothing" and "exact matches" were on. (Though I think exact matches doesn't work). Forbidding/destroying all leather/wood armour might've helped with the thing. (My marksdwarves now use steel high boots, because leather boots are evil and only go to right foot, apparently.)