The guys in the video are cossacks, dancing was seen as a form of regimental show, so they would work together and it would be very structured and regimented.
As for what the song is about, have no real idea on that one. Its music it has a good tune, and its kinda fun to watch. Enjoy it for what it is, no point reading to much into it as it spoils the experience.
...How happy is the blameless vestal's lot!
The world forgetting, by the world forgot.
Eternal sunshine of the spotless mind!
Each pray'r accepted, and each wish resign'd...
Alexander Pope "Eloisa to Abelard"
The iron ore feels its self needlessly tortured
as it goes through the furnace.
The tempered blade looks back and knows better.