What do you think, if bethesda would improve it making that the combat multiplier affects not only you but all the non-hostile creatures, for example:
In master difficulty you deal *0.5 damage and take *2 damage from enemies, but your follower, npc allies that support you in towns or even the horse is not applied with this penalty. What do you think if bethesda make it applicable to all creatures? So in master, your follower, horse, etc... deal *0.5 damage and take *2 damage too, like you.