Deidara needs to be close to his opponents to be able to land attacks and be sure it hurts him. Kakuzu with lightning element could neutralise his clay bombs, and if it's needed, he has his doton defense to protect himself(i think it could resist against C1,C2 at least, maybe even more). His monsters could fly and make combos to hit Deidara and that makes it even much more difficult for Deidara to attack. Even if Kakuzu somehow get killed once, he has 5hearts, so that helps him to survive and look for a better strategie to win.