In my most recent survival, I made my entire house underwater, including the farm. Where I have the cows in my farm, two witches spawned due to the low light level (fixed). I started fighting against them, but when both witches were throwing potions one hurt the other one, so a fight between the two witches started. All my cows were killed due to the splash potions, and both witches are still alive.
My question is, can a fight between two witches end?
From the Minecraft Wiki under the trivia section:
If a witch hits another witch with a potion, the witch who is hit will become angry and target the other witch, however it is impossible for either witch to kill the other (without help from a player) due to their use of healing potions and their resistance to each other’s splash potions
So from your comment, you kind of hinted at this. It looks like the healing potions make it impossible for either witch to die from one another and end the fight. Unless you intervene, they will continue to fight.
Source : Link , Question Author : spund3 , Answer Author : Timmy Jim