On Pandavas and Kauravas

I wonder why there were 5 Pandavas. 2 of them were pretty useless and added pretty much no value to the story! As a matter of fact, out of the 99 brothers Duryodhana had, only 2 or 3 had any real contribution to the story. For the rest of them I guess the whole purpose of existence was to be slayed in the Mahabharata war by Bheema. Oh yeah, the other purpose was to demonstrate that Maharshi Ved Vyasa knew of so powerful test-tube baby generation techniques which are not even possible in our current times.