What do you mean by pretending to be psychopaths? People with high empathy are really great at reading people, fantastic manipulators. Why do they have to pretend to be psychopaths, when they basically can do the same trick that psychopaths do? They might not want to manipulate and harm in a way that psychopaths do, because they might have great sympathy that psychopaths do not possess.
However, empathy has absolutely nothing to do with intolerance toward sufferings.
People really have a hard time understanding what it means to have empathy. They just assume "empathy" is something good and whoever possess such a good thing treat people nicer. That is absolutely wrong. Empathy means feel what other people feel. Narcissists are famous for having no empathy because they don't feel what other people feel. That never means that narcissists want to cause pain to others. In fact, narcissists can feel guilt, which is a direct result of failing sympathy. The problem is never that they want to mistreat people, they just don't want to know, or pretend not to know that you are suffering.
It can be argued that psychopaths don't actually have empathy, because they don't feel emotions themselves. It is kind of pointless to feel whatever you feel if they don't really give a fuck about what they feel in the first place. However, scientific proofs have shown that psychopath actually possess great intellectual empathy, and that is exactly how they read people. True, they don't give a shit, but that does not necessarily mean they don't want to know or they don't know.
Narcissists don't want to know, psychopaths don't give a fuck, and Autism does not actually know. That is how it works.
Great empathy does not mean great sympathy. It means better understanding and sharing for whoever possess it. It also means potential manipulators, because they know what you are feeling. However, it makes it hard for people not to pity if they are feeling sufferings themselves, unless they are psychopaths and emotions means nothing to them.
People with a lot of empathy cannot pretend to be psychopaths. They are either psychopaths, or they are not.
The problem of psychopaths is that they don't give a shit about anybody's pain, including themselves. Feeling other people's painful experience is absolutely meaningless if you don't even give a fuck about your own painful experience.