Oh, I see... that makes perfect sense.
You know, BofP and Doraemon has many things in similar. Both features what Japanese anime/manga consider to be the perfect group of main protagonist and support character combination:
Doraemon:
Battle of the Planets:
Both shows have the main hero, a girl for the hero to have romance with, a short and wise dude, a big and strong brute, and a fifth character who is usually to compliment the main hero or to form a contrast. Usually, a more kid oriented show would focus on the main hero and the fifth character's collaboration, while the more mature themed show focus on their differences and conflicts.
Even in Dungeon & Dragon themed RPG video games, you can see this similar set up: the main protagonist, a Babarian, a Rouge, a lady (usually a healer or a ranger) and a anti-hero (especially true in Bioware's RPGs, like Mass Effect.)
Perhaps it is a summary of an ideal society (assuming their collaboration:) We have leadership, military (strong man), art/culture (more pacificist, feminie side), intellectuals, and a perosn who is always there blowing the whistle to keep the balance in check.