I do not have such figures, so I can only judge by photo.
The summer field uniforms of Cossacks and dragoons are very similar (especially on the figures). But there are some elements that allow us to confidently distinguish Cossacks from regular army soldiers.
Cossacks had a saddle of the Asian type, in contrast to the army cavalry. Accordingly, they did not use spurs to control the horse. But, since Cossacks acquired uniforms and equipment at his own expense, options are possible here and we can neglect this rule (the figures discussed have an army-style saddle))))
Cossacks (except for the Caucasus, having a special uniform) always had on their trousers a wide colored ribbon (I do not know the term in English). Similar to what many European generals wore))) The color of the strip was the instrumental color of the troops (Don - scarlet, Siberian - red, Ural - raspberry, Transbaikal - yellow - and so on). Army cavalry did not have such a colored ribbon.
The Cossacks did not carry the rifle in the same way as regular cavalry soldiers did. They wore it over the other shoulder (vice versa). It was connected with the old Cossack tradition.
dragoons
Cossacks
So for most of the signs the figures Tsuba - are Cossacks.