Of the thinkers, I would say NTPs. They have both Si-Ne and Fe-Ti. That puts them with the SFJs. Fi types aren't really compassionate, to be blunt against my own type. INTPs seem to dislike conflict and emotions, and avoid those. My personal impression of them is as a soft type--like the ISFJ. And the two INTPs I know well are very compassionate, and for years, I would never have thought the the guy INTP I knew was an INTP. I would have said a feeler, but my daughter has become good friends with the family, and she's convinced he's an INTP, and shared all kinds of details about him that have convinced me that he shares my wife's type, and my wife is the other INTP. She is very compassionate, and caring of both her kids, and others' feelings. She also comes up with novel or compassionate ways of helping people. She keeps special stocks of food in the house for homeless people who come asking for food. These foods store well, don't need cooking or special ways of dealing with or handling, but are full of proteins and healthy. She also keeps ourselves in bread and fruit to give them. In the winter, we probably have someone almost once a week. I would have never thought of this sort of thing, but she did. I don't see any INTJ or ENTJ I've known who would think of these things. The ones I've known would probably just tell such folks to get a job--or maybe offer work to them, or something less overtly compassionate. Me? I'd give them money were it not for her. I know the sample size is small, but my experience with NTJs and STJs is more extensive, and "compassionate" is not how I'd describe them. They are caring, and can be kind, but my impression of compassionate doesn't fit them, but it does fit the INTPs I know, and if you look on the INTP page on celebritytypes, there are some folks there who one would have a hard time calling ruthless or harsh.
I dunno... maybe I'm biased, due to my wife. ;-)