Help identifying an outfit

[Orgetorix]

Does anyone recognize what kind of outfits these guys are wearing, or what the things are they're holding? One of these men may be my great-grandfather, I'm not sure. The caps look militaryish, but the lack of any insignia on the coats made me wonder.

 

[Feraud]

Are they holding stockwhips? Could they be drovers?

 

[Orgetorix]

Ah, that's possible. My mental image doesn't really associate garrison caps with cattlemen, but I suppose anything's possible.

 

[V.C. Brunswick]

They do look like they're wearing army uniforms from the WWI period. The overseas cap worn by the one on the left looks French-made. The dusters and stockwhips suggest that they might be members of an artillery or quartermaster unit which would have utilised draft horses or mules.

 

[kiwilrdg]

I have not been able to see the picture but the descriptions sound kind of like some of the units that formed in America and went over to Spain during the Spanish Civil War.

 

[carldelo]

Horsemen from the Caucasus or the steppes of Russia? There's something exotic about such outfits worn without military insignia...
Could they be camel drivers?

 

[Orgetorix]

Another shot of the guy on the right - anyone recognize the uniform as to branch or unit of service? Cavalry?