DrZoidberg
Contributor
Isn't the fact that it is an army, in itself, something to be worried about? What does the "Islamic" bit add?
It tells the infidel that they are fucked.
Historically a Christian overlord behaved atrociously. A Muslim overlord less so. I actually don't think this has anything to do with religion. I think it has to do with regional politics surrounding the conquering. Islamic conquering has historically taken place in more civilised and affluent areas of the world. There was an incentive not to kill people. The Ottomans treated their Christian and Jewish subjects relatively well. The Christians following the colonisation of the post-industrial world was about as bad as it can get. Christian/European settlers primarily just wanted land, so they had little incentive to give a shit about the conquered peoples. I'm including Nazi-Germany into this same general vibe.
If you are making a case that religion matters I don't think history is on your side here.