You might want to look at more than just HP and MP... I'm not sure if they change, but they might. I'm too lazy to look it up myself.

If they don't, it is likely because the jobs have a base stat at level one (or two, since as far as I can tell, it is completely impossible to get a level one character), as well as their average stat growth. With the highest level member of your clan being only level four, the characters haven't gotten a chance to build their own unique stats yet.