I used to be a certified shooting instructor.
Not all, but a lot of so-called recoil hyper-sensitivity can be cured by instruction in proper rifle shooting techniques in regards to FIRST getting a rifle that fits or modifying a rifle to fit a specific shooter, proper stance, position (in relation to target), posture & holding and breathing fundamentals when aiming & shooting.
I've seen many people complain about a hard kicking gun and the reason was that the gun didn't fit them. Guns need to fit properly just like pants or shoes need to fit properly or extreme discomfort can result especially when shooting really powerful rifles. A person might feel battered by a 308 Win and another feel quite comfortable shooting a 375 H&H.........the reason........one shooters rifle fit him and the other persons rifle didn't fit him.