it's possible that some of them are the same sub though. But it does make sense to have 2 093s + 1 094 in Sanya. I'm also thinking that there might be a 091G in Sanya. And then I'm guessing there are probably 2 093s in Jianggezhuang. The additional one might be visiting there, it makes sense to me for things to be in pairs. And probably 1 other undergoing sea tests and the final one in Xiaopingdao. Eventually, probably at least 2 in each of the bases.
I was researching about the possibility of ships assigned from a different base or fleet would ever go to another base that belongs to another fleet. Based on the patterns of surface ships, which I also believe holds the pattern for deployment also for submarines, this seldom and I emphasize rarely happens.
Like for example, we never saw the 051C in any other base rather than Dalian's. Nor have we seen the 052C or 052B in any other base except in the SSF,and the only time the ships appeared back in Shanghai was either for some ceremony or for maintenance with the shipyard. For the most part these ships pretty much stayed in Hainan. I have never seen the 167 in any ESF or NSF base either.
Chances are much higher the subs we see on the three bases are unique, although its possible the subs in Jianggezhuang and Xiaopingdao may still interchange as both are NSF bases. But chances are very good, the subs in Hainan we see in Google Earth are not the same as the ones that appear in Jianggezhuang or Xiaopingdao.
A boat assigned to one fleet, pretty much stays that way throughout its life.