Could be Cossacks. Cossacks have been fighting since the 1990s: they participated in the two Chechen wars of 1994 and 1998, and now Ukrainian civilian armed forces are fighting Ukrainian government forces in Donbass.

Gurkhas only participated in some ground defense missions in the Gulf War after the 1980s. He appeared in the British army as a mercenary at most.

But Cossack and Gurkha are both tough. Gurkha soldiers are one of the best infantry in Indian subcontinent, especially in mountainous areas, plateaus or other rugged areas. Their endurance is amazing. Cossack is the best cavalry in modern Russia and Europe, and now there is a tradition of training horses to ride. Moreover, from the Soviet period to the present Russian Federation, Cossacks have received a good education. Cossack veterans who participated in Ukrainian civilian armed forces can skillfully use heavy weapons and are also commanders of the army.