You mean the 83 Syrian troops killed by the U.S. aka “ the air force of ISIS” ?
If you get any honest reports from Aleppo ( not western media)
Like this canadian independent journalist you can start to,get a better idea why people are running for govt areas, not away
https://m.youtube.com/watch?v=AbIqdRvOnww
Assad has killed not tens but a hundred thousand or more Syrians ( by even low estimates). The number killed by IS is a mere fraction.