In Dr. Faustus, due to the benefits of it being s staged production,
the playwright can put out all 7 vices on the stage and allow the
audience, along with the actors themselves to see it.  Dr Faustus sees
all of the 7 deadly right in front of him on stage, represented by an
individual person.  While we debated it in class, I believe the reason
the playwright chose to do this was so Faustus could see his ego ideal
which is the identification with authroitative person who makes you
feel inferior.  In this way, by Faustus seeing all of them, he can see
his true self and focus on his involvement in all of these 7 sins,
weather he is more involved in some rather than others.