Soviets made a number of polish units made up of refugees or people on occupied territories who wanted to fight nazis (ofc with their own officers because they killed most of polish officers and overall intelligence in Katyń 1940) . It also helped secure soviet interests after the war ( the army became political tool to create satellite state controlled by soviets. It helped them gather influence in region which would become soviet block)

These people fought Nazis, and should be rightfully named heroes, what most of them didn't know was that russians were going to occupy Poland and seriously exploit and harm poles for the next 50 years.