(This is a question based on an event. A shaaloh was asked. The object of the question is to examine the underlying reasons for the dinim in the situation.)
A family minyan meeting once only on Shabbos day, consists mainly of Kohanim and Leviim. There are enough others to give the following aliyos to the Torah: Kohen, Levi, Yisroel, Yisroel, Yisroel, Yisroel but there is no other Yisroel to make up the seven. There is a Levi for Maftir.
What are the factors that govern how the aliyos should be arranged?
Obviously the seventh must be a Kohen or Levi. Is it permitted to call him last?