The fight starts with 1 Greater Behemoth, and 1 Behemoth on opposites corner of the map. After the regular Behemoth is defeated, a King Behemoth and another regular Behemoth will appear. After those 2 are defeated, another King will appear on the bottom left.
All of them are Beast type, so you can use Behemoth VC to get some beast killer. They are also all Dark element, so Light units are recommended. Sometimes any of the Behemoths (or just King and Greater) can do an "instant death" attack, so you might need to bring some revive items or skills.
The Behemoths have high jump, and the area has a lot of different height levels. This gives them more advantage and makes it more difficult to chase after them.
Most of their attacks are physical, so you'll definitely need a tank. If you have Tidus as your tank, you can have him cast Hastega on your team and do a "turtle" strategy to finish them off 1 at a time.
At least 1 good non-Light physical tank is needed to grab their attention, it helps ensure that the instant kill abilities are used on them.
Yuna can help with re-raise and more revive skills with her Summoner of Spira as subjob, but other healers can still work since you can just bring a phoenix down item.
Sakura is pretty good here since she deals high damage and can use Light Blade plenty of times.