It seems to me that with the Three neading to be together for the final battle that they are like one body. Rand is the bodys strength in the body, for he controls Saidin and the Aiel, Armies of the land follow him, as does the Black tower. And Mat is the Brain. He is the crafty one, it will br his army skills that will concour the Darkfiends. It is his job touse Rands strenth. And last of is Perrin. Perrin is the heart of it, he leads the war on a Moral scale, without him, Rand is just holding a grudge againt people that killed him in a different age, Perrin makes Rand use his streanth for good causes, makes him relize when he has stepped wronge. So it seems to me that they are all one body, without streanth of Rand it will be killed, without Mat's brain it will be to stupid to do anything, and without Perrin, the Body has no perpose, no guidence.