Are China Eastern Airlines, Jiangsu, Nanjing and Wuxi treated the same?

I'm not particularly sure, but some friends have discussed similar issues before, and they all think that the salary should be similar. After all, they all belong to Jiangsu branch, but their territories are different. If we say which is better, of course, the main branch of Jiangsu Branch is still in Nanjing, Nanjing is the headquarters of Jiangsu Branch, and Wuxi is just a branch ... Have you finished the training? Can I ask you a question? Is English difficult in training? thank you