Wells had been learning from Yale since he was young, and ever since Yale had become Wells's teacher, Wells's brand had been deeply imprinted on him. He was determined to help Wells become the clan leader, and so he had taught him with great care.
The reason why Yale was so dedicated to teaching Wells was not only because he was Wells 'teacher, but also for the water buffalo clan. Although the water buffalo clan had a very high status among the Tauren clan and had many famous prophets, if Wells lost in this battle for the throne, he would definitely be suppressed by Gasol. By then, Yale's life would not be good. The water buffalo clan that Yale was born into would probably not be in a good state either.
It was precisely for this reason that Yale had to help Wells ascend to the throne. Only by doing so would he be able to ensure the benefits of the water buffalo clan.