I don't think team battles will happen
maybe among the lower ranks but in my eyes they are very slim
I remember one of the chapters title or little phrases. "Can the straw hats handle CP9's awesome team work skills?" I think it was the first time they engaged or was it on the train with Blueno x Calipha but anyways I don't think it's just the two or three members Kaku, Calipha and Blueno that compliment each other in team work, all the CP9 members must have some sort of sense of teamwork
Maybe a scenario like in the foxy arch where Zoro and Sanji are beaten down and get pissed then work together to make awesome combinations and coordination… but that would mean a Kaku and Jyabura vs Zoro and Sanji.... but the main fighters always go solo so I imagine if there was a team battle that Nami and Soge King vs Kalipha and Fukurou since Nami can learn from Soge King in battle and such..... but my number one match up is still.....
CHOPPER VS BLUENO!!! I will cry an ocean if this doesn't happen