-Fang Pi Clang relies on insane amounts of damage and 2HKO's, (making them somewhat less effective in Elo) while having relatively weak power and performing somewhat poorly against SOA and attack manipulation. However, their Elo viability has recently been strengthened by Zhu Tang and Kusuri, adding some life gain and defending capabilities.
-La Junta is a more high-powered clan than Fang Pi Clang. They are especially effective in mono because of their many amazing support cards. They are also slightly more balanced, having a wide range of different abilities, making them somewhat less shaky than Fang Pi Clang. Of course, they have generally low damage relative to Fang Pi Clang and have trouble against SOB.
-Ulu Watu has straight ridiculous power. That sums them up for the most part. They perform relatively well against SOA and SOB and can use their high power to take down attack manipulators. However, they are notoriously weak to DR's and have generally mediocre damage.
-Bangers are known for being a good 2HKO clan, which many could argue is a setback for them in Elo. However, their damage is always useful, and 2HKO's are still very possible. They have less fear of DR's but more for both SOA and SOB, especially SOB, in my opinion anyway.
I hope I was helpful. I believe that no clan is "better" than any other, but you're welcome to your own opinion.