well, red/white pennants are not unusual for any kind of lancers, and I thought I'd see the white/blue/ red of russia
but now, that You named it, some cavalry uniforms could be recognisable as polish...
and the style is clearly imitating impressionist style brushstroke, therefore implying "oilpainting" is not that much far fetched
this one is great!

he has japanese and viking motives as well