Who killed whom in Syria?

I am now confused.  All along we are told that Bashshar killed 300,000 of "his own people".  And now David Ignatius is bragging that: "One knowledgeable official estimates that the CIA-backed fighters may have killed or wounded 100,000 Syrian soldiers and their allies over the past four years."  That would be a 1/3rd of all people killed.  But to kill 100,000 Syrian soldiers and "their allies", how many civilians were killed among them? Would that add like another 100,000? or Less?  Not sure.