Huh. Devil's Advocate for me seems like such a weird thing for me to do. I mean for one thing that is just creating conflict, something that me and most ENFPs I look at hate above all else. It is hard to imagine purposely creating conflict, especially when you are trying to connect with others and accomplish something. Constructive criticism is useful, but just being argumentative in order to be the other side gets annoying. It gets really frustrating when you come up with a great idea and people argue against it and make you feel like it was a mistake and then later for them to say that they agree with you and were just playing devils advocate.
For another, ENFP are idealists and like INFP are very passionate about their ideals. This means when I have something that is important to me and is something I take pride in I already have done a lot of research on it. While occasionally a devils advocate will bring up something I haven't thought up, that is more the rare occasion as I have my own devils advocate to deal with and usually I've already considered it.
That isn't to mention how inauthentic it feels to be devil's advocate to me. Taking an opposing stance to something that I feel passionate about to me feels like a betrayal to my own self. It isn't that I can't view alternative viewpoints as I usually have considered them, but just that to represent those viewpoints feels inauthentic. I like taking a side and sticking with that. If there is compelling proof that I'm on the wrong side I'll switch of course, but i'm not going to advocate for a position I don't believe in.
I also like efficiency and this might just be personally me but devils advocate and such slows things down when there could be action and progress being made. Instead of harnessing the enthusiasm while you have it, you have to go over the things you have already talked about and considered. Sometimes I really wish if someone opposed something they would just take a stance right away openly and if they agreed bring up ways to improve the idea rather than argue against it.
Usually my defense against groupthink is self discipline and the importance of my ideals. I don't like conflict but I'm not afraid to go against a group if going along with them compromises my own integrity. I'm not afraid to call out dangerous behavior or ideas even if it endangers my status within the group.
That being said, it is easy to get caught up in circlejerk as the aversion to conflict and the strong idealism can encourage that. I guess that is the problem of having a shadow Fe. I like harmony because it avoids conflict, not because it is a goal in of itself.
As an aside, this is why I don't like online tests and such. Usually they have these vague questions and work on a letter by letter basis. Like consider ENFP vs ENFJ. ENFP has primarily Extraverted intuition backed up by their introverted feeling (inner values and feelings). ENFJ is Extroverted feeling with introverted intuition backing it up. All the other things are reversed as well. If you look at the functions they seem very very different but because of how a few questions on an online test score towards between judging and perceiving you would think it would be similar. Some vaguely worded question could put you in almost exact opposite to people like you. Online tests are the worst with some questions that are completely irrelevant.
Looking at the functions I would put both ENFP and ENTP as creative thinkers. Most things usually back this up. After all, ENFP have Ne as primary and Te as tertiary. I guess the most important distinction isn't whether you are thinking or feeling but rather do you value idealism and authenticity more or do you value pragmatism and ingenuity?