I think OP wants the Jobs and Classes to have separate levels from one another. I never played FFXI, but from what I saw in Wikis, your level reverts every time you change, the base Classes were the 6 originals for that game and everything else was a Job, but the jobs started over from level 1.

The only trouble with that was the Jobs in 11 did not have a heavy reliance on their base classes like they do in 14. It would be interesting for split jobs like SMN and SCH to where you can set each one to its own stat bonuses rather than splitting it down the middle in order to be able to play both SCH and SMN.