Bedrockgames
I post in the voice of Christopher Walken
Disease, condition - whatever - its a mechanic. Want more realism? Don't call it a disease; just call it a consequence of getting hit by a big sword and have the save happen all the time (or if damage above a certain amount is taken, or whatever - set the condition to what you like).
Personaly, I don't like it to be the default condition as I don't usually like things that grim and gritty - doesn't mean it's not easy to do.
Or you could get rid of the healing surge since that is what is causing issues for people.