If it's in 4 then I haven't seen it, but not once in Fallout history do I recall a "They're turning mad" phase. Charisma roll to successfully turn them sane or put them down like old yellow? It's been stated feral ghouls are mad because of brain deterioration or something, but I have yet to actually see the process itself.
Likewise one would think there would be a "half sane and half not" groups here and there. As in "Turning but haven't quite lost it yet". There's that group in "goodneighbor" but they're just plain old bad as opposed to nuts. Even though it's a "bad for equal rights" way. Something about John feels very Barbossa from Pirates of the Caribbean. I'll have to pick him up as a companion next time.
Speaking of which, I like how the wild canines have been done. I've noticed that some of them growl if you get near yet leave you be if you keep distance.So half sane ghouls could, what, creepily crawl around a bit and squat as if to pounce as you get near or something?