I'll start with the Bolshevik Commissars (a somewhat serious oversight in a game about the Revolution...) - they currently have the same uniform as generic White (!) engineer units. Kind of odd. Not sure what to replace them with, but the pictures used for Cheka/Red Guards would do. Though ideally they'd get a unique picture, being Commissars and all.
I'll set a good example by providing a picture -
(a website claims that this is a "Commissar of a Food Squad," which I take to mean someone commanding a requisition unit engaged in prodrazvyorstka - regardless, the leather jacket makes him a pretty stereotypical example)
For now, I'd limit the thread to obviously out of place pictures, rather than disagreements over what exactly they should be (I'm not all that happy with what the red sailor detachments look like, but they're not obviously out of place).