For a war crime to be genocide the number does not matter. It could just be 10 people that someone killed. But the crime needs to meet the minimum criteria set forth by the genocide convention. Per those criteria, Israel's murder of the Palestinians count as genocide. Now there are many other war crimes, such as using chemical weapons etc., But not all war crimes are genocide. So again, your example fails.NOT ACTS OF GENOCIDE.....
There you have it folks. Killing 300,000 isn't genocide. Its perfectly acceptable losses to civilians in a proxy war between Iran and Saudi Arabia. And Bashir using cluster bombs and chemical weapons is also just fine too. Nothing to see here. Because there aren't any Jews to hate.