I thought Grohl seemed like an ESTj, myself. In Foo Fighters, he's known for making his band members do a ridiculous amount of takes to get just exactly the right sound, which sounds like ESTj or ISTp to me, and his demeanour seems fairly extraverted to me. On the other hand, if he were an ESTj and Cobain an INFp, they would be conflictors, which seems kind of improbable. Hmm. Maybe ISTp?
Yeah ISTp works...
I'm referring to Gulenko's DCNH system of subtypes. There's a thread about it
here. In a nutshell, it expands on the regular subtype system by splitting each subtype into two more: rational subtype gets split into the more extraverted "Dominant" and more introverted "Normalizing" subtypes; irrational subtype gets split into the more extraverted "Creative" and more introverted "Harmonizing" subtypes.
I've found that the DCNH system allows one to more accurately describe the variation within a type. Sometimes a person can come across a variant of a type that he hasn't encountered before, say to himself "Well Person A doesn't act the same as Person B, who I
know is Type X, so clearly Person A isn't Type X," when in reality Person A really
is Type X, just a different subtype from Person B. I'm pretty sure this is what I was doing in this thread with Cobain.