Oh, islam is currently uncergoing a reformation. Its called ISIS. Its their thing, scripture only and all that?

Anyways, some things are human constants.
For instance, only around 30% of people in an army would shoot in the general direction of the enemy. And only 2% would shoot to kill just like that.
Modern training gets around that by making you shoot before you even have time to think about wether or not you will shoot... Other than that, youd only have the 2% of genuine sociopaths and maybe some who shoot out of love towards their comrades, family, what have you - thats how the romans did it, before you were seeing actual battle you were likely camping with your closest comrades for quite a while.
Of course, it wasnt as big of an issue back then anyways. Animals fight, too, they rarely hurt each other - they try to scare each other off. With a firearm, sure, you can shoot in their direction and would hope that happens, just go away! But thats not very effective... On the flip side, if you train people to shoot before thinking about it, you will find there will be problems when they get home...

Another human constant is you wont find a society that is mysoginistic. You will have no problems finding things which you perceive as such in foreign cultures or history, for the same reason, youll just ignore all context.
Islamic genital mutilation for instance is perceived that way by us. When it is usualy the decission of the mother, done by a female relative and men over there are more likely to oppose it than women over there are.