southern master made sense to me and I didn't think anything was wrong with it. imo, thousand master sounds kinda odd. you dun often hear of masters with a number for a prefix(usually a suffix, like "of nth item").
but then I did wonder where the southern came from....I just thought it would be explained in the future. but with the japanese version being like that, I dunno.
overall though, it doesn't bother me very much as I"m much more tortlant of translations and small changes.(sometimes I feel like I'm surround by hardcore people....but then again...I am speaking on anime con forum, but offline still....)
oh btw, something I remember with fansubs, remember they aren't always perfect. of course, this will depend on what quaility you get though. I dunno about anime, but on naruto fansubs, there was some major mix ups with rasengan supposely having 8 lvls(its just the 3 that we see) and akatsuki's suppose husband(just a partner) more recently.