Okay, so having done the White Mage I'm ready to jump in and OSH-erize more job classes and races from Final Fantasy Tactics Advance. I liked the game well enough to play (albeit rather repetitive after a while), but as an RPG GM I really liked the non-D&D races and the jobs/classes. I actually ran a game using the Big Eyes, Small Mouth rules for a while with race and class templates built based on FFTA.
In that game I had the races and classes separate so the players could mix and match. But FFTA has most of its jobs race-specific, rather like how the Old School Hack and the original D&D had race-as-class. So I have to decide whether or not to go with the set race/job combos as presented in FFTA. The set combos are true to the original and in keeping with OD&D.
However, FFTA was able to code in racial bonuses/handicaps by varying factors for gains in attack, defense, hit points, etc. Those factors were very fine grained. For instance a human Black Mage gained 4.4 Magic Points per level, while the Nu Mou version gained 5.4 points per level. But OSH is specifically designed to be "low rez" rather than fine grained. So at a minimum I would have to decide how to design the multi-racial classes: Thief, Archer, Black Mage, Illusionist, Time Mage, and White Mage (happily, only 6 out of 35 jobs). Well, actually, I'm not planning to do every single one of the those jobs. There are a couple which I just plain don't like or don't care enough to work on and a couple which seem too similar to bother with.
But I figure that means I have to either:
1. rework the job charts so that all jobs are uni-racial (all jobs are race-as-class);
2. have no racial modifiers of any kind for any job (so there's no effect in multi-racials);
3. or separate race and class, as in later D&D and Pathfinder.
With option 1, I have to take a hammer to the existing job tree and make quite a few arbitrary decisions on which race is the only one to get a particular multi, such as White Mage. There is also the question of what to do with the jobs which use those as pre-requisites which would be "orphaned". For instance, the human Black Mage leads later to the human-only Blue Mage and the nu mou Black Mage leads to the nu mou-only Alchemist. I really would have to totally gut the entire job chart. That sounds like a lot of work for little gain.
With option 2, things are a lot easier. Each can be built without any worry about the races. But in FFTA the races did make a difference--they were supposed to make a difference so that choosing a particular race/job combo mattered tactically in game play. Then again, if the races don't have any features which influence the class then you avoid power-gaming. People won't make selections based on which one provides the most bonuses to a class "build". I like that idea.
Finally, with option 3, I'm on familiar ground--split class and race as in Pathfinder, etc. This option allows me to make separate races which, this being OSH, would also be usable outside of "Final Fantasy School Hack".
After some reflection I've decided to go with option 3. I prefer to give players a wide range of options, because to me that is a big part of what makes RPGs fun, and so race-as-class is out. However, to keep the overall task reasonable I will convert only my favorites from the game rather than trying to do all of them. For the races I will do just the viera and nu mou. For the jobs I will do just the White Mage (done), Black Mage, Red Mage, White Monk, Dragoon, Templar, and maybe Sage.