Akatsuki wins by default...If you restricted friendly fire then we would have something called match,but as it is Akatsuki stomps.
Battle starts,s**t happens,Deidara goes airborne.Prepares C3,drops it,Tobi warps "insert random akatsuki member"then goes intangible,and Deidara nukes the the landscape and reverts the civilization back to the primitive age.
If anyone survived the nuke,well then they have to face Tobi his biju's,Deidara and his nukes,and the "random akatsuki member" that Tobi warped,good luck to him