stat growth is completely dependant on the main job and sub job you use (mostly main job). As you main job gorws, so do that stats that that job requires (ei HP for monk, MP for mages etc) and as far as I can tell its not random. a level 20/10 war/mnk taru will have the exact same stats as another war/mnk taru ha;fway across the world. only difference may be weapon skills depending on what they use, and weapon and armor modifiers, but that is it.
don't know if that clears it up for you or not, but I tried.