ENTP are often big thinkers with a social comedian persona, or a variation of the theme. Does anyone find it a bit surprising that there's more than 1 side to a person?
As I've seen it, ENXPs can be quite similar. It's usual to see emotional, people-loving technical ENTPs as well as ENFPs. After all, their T and F functions are in secondary and tertiary positions, just places and intro/extroversion switched.
Yeah, ENXP's play may be the most superficial kind there is.. it's publicly so, it's an act.. entertainment.. it's a parody on what's superficial. It may be over-the-top. ENTP's are masters of systems, they're confident with extraversion, whimsical, spontaneous, so it's natural they choose a superficial act as their "funny mode" behaviour.
I think ENFP's are closer to their core identity in their "people" mode, funny random things (Ne) depending on what people feel (secondary Fi), giving less reason to blame them about superficiality. ENTP's public funny act works more with Ne Fe, of which Fe is superficial, and it's use is somewhat planned with Ti.
ENTP's core is not superficial in the least, it's quite ok contemplating with charts, books and all the esoteric information for as long as it needs, no matter how difficult or obscure it would be - as long as there's a reason to do it, and for ENTP, there often is.
Then again, ENFP's core (Ne Fi) is a bit more people-dependent than that of ENTP. Whereas both can do their information-gathering via books and other media, T-like experimentation is less reliant on people than experimenting with F. So, ENFP probably feels more reason to spend time with people, giving rise to suspicions it's them that's actually the more superficial one.
So all in all, they're both very much ideas persons, with their interests having a wide range from profound to the superficial - I'd say more so than all other types.