It's not just a matter of health and damage. I don't like to much when difficulty settings change just these things. Actually in the main quests enemies just shoot one time in wrong direction. Look at you for 15 seconds, miss another shoot and the third or 4th time they hit you. I don't want to die every 30 seconds becouse enemies one-shoot kill me, I just want to have to run around and hide and run after hidden enemies...like in other activities here on destiny 2