The IDF claimed the uncovered footage provides further evidence of Hamas using the civilian population as human shields. Dressed in jeans and a casual grey shirt to look like a civilian, the man is seen later walking through the bomb-blitzed streets of Gaza with the missile hidden underneath a blanket.
Where’s the 8k soldiers claim from?
According to here Hamas has 20k-25k members: https://en.m.wikipedia.org/wiki/Hamas
8k dead Hamas militants estimated by Israeli military a few weeks ago. Overall strength was 20-25k militants at the beginning of the war as you said.
You need to remember that Hamas is both a political and military organization - 20-25k Hamas members doesn’t mean 20-25k Hamas soldiers.