Well... I found a decent solution at least for my melee partners, but maybe this won't work with mages... or others configurations, I don't know. Read this thread. http://forums.nexusmods.com/index.php?/topic/989230-apply-difficulty-settings-to-followers-follower-damage-reduction/ It seems that the console command to decrease health (or magicka or stamina) is this "modav health xxx". Try with different values. With "getav health" you can check the health of the follower. And that's the only way that I found, I decreased a lot of health and attack damage to my partners so now they go to the ground when they fight with powerful creatures. I don't know if this have secondary effects, I hope not, try this at your own risk.