Just because someone is an ESFJ instead of an ENFJ, doesn't all of a sudden give them a less directive leading style.
An ISTP doesn't have a more directive leading style than an INTP. It is just that the INTJ is MORE directive than the INTP and the ISFP is LESS directive than the ISTP.
I know that there is a theory out there which has extraverted directive types and so on.. however, Keirsey is only comparing each type relative to others in its own temperament. I think that might clear up some issues.
Guardians like order and will naturally be bossy types.
Artisans like spontaneity and will let more things slide.
I prefer this
Directive: INTJ, ENTJ, ISTJ, ESTJ (2 Guardians, 2 Rationals)
Directive/Informing: INTP, ENTP, ISTP, ESTP, INFJ, ENFJ, ISFJ, ESFJ (2 Rationals, 2 Guardians, 2 Idealists, 2 Artisans)
Informing: INFP, ENFP, ISFP, ESFP (2 Idealists, 2 Artisans)
I think this makes more sense.