Please note the number of Polish military listed as "prisoners and missing" was 400,000 along with 50,000 to 70,000 killed in action plus another 150,000 wounded.
I have google-searched for data on the fate of these 400,000 prisoners, without success.
However, at least one source says the total of Polish military deaths was 400,000. It does not say how many died at the hands of Nazis versus Soviets.
It would be somewhat interesting to learn how many of these Polish prisoners were treated "correctly" by the Nazis, and how many were just murdered, along with those 8 million other Polish civilians.
A couple of points.
I thought I had posted on another thread that the the Germans reverted the Polish enlisted men to civilian status - I think that was about 1941, but I’m not positive of the date. Some of those subsequently died of various causes (including execution and allied bombing) but the mass murder of POWs was a Soviet sport. In any event, those who died/were killed after returning to civilian status don’t count as POWs killed.
Your number killed looks like it may include AK and perhaps Jewish resistance forces. (Warsaw was just one of a number of battles fought by the AK) (Note that while the Germans took brutal acts of retaliation against the Warsaw civilians after the uprising there, the surviving AK were treated as POWs.) I’m not sure if it includes Polish communist units that fought with the Red army. It does likely include Polish units that fought with the British. (Monte Cassino, Arnheim, for two notable examples).