Here's some stuff for discussion:
INTP vs INTJ: 5 Ways to Truly Tell Them Apart
INTJ vs INTP: Core Differences
Thought the personality junkie angle was interesting -- compare their obsessions with Fe vs Se concerns. (They've advocated this too with INTP vs ENTP, in regards to Fe vs Si angles.)
lolz. Honestly, I think with INTPs intelligence is expressed in our ability to get a job across the finish line with as little work as feasibly possible. In fact, I think we spend a lot more energy trying to devise the most elegant solutions to accomplish a goal with the least amount of effort needed.
Doesn't mean we don't care about the task. But doing everything the straight-forward "roll up the shirt sleeves" way feels banal and unimaginative by nature, we're always looking for some kind of streamlined process.
I have had to learn sometimes to plunge ahead and put in the sweat and toil and "do the obvious." Also, I take my responsibilities seriously, regardless of how I fulfill them.
I haven't really met E3 INTPs either; usually it's e5 or e9 by nature, depending typically on their tolerance of conflict with / interference by others.