I usually only have three "jobs" with materia: Black Mage, White Mage, and Summoner. In my standard party of Cloud/Tifa/Cid, Cloud is my black mage with the most powerful magic materia, Tifa is my white mage with the healing materia, and Cid has most of the summon materia. There's obviously some overlap, as, for instance, I'm not giving Cid all of the summons, but that is generally the division. I distribute command materia and others as-needed, with everyone getting a Magic Plus and Enemy Skill.

Your classes are very interesting and well thought out. The physical-only classes will suffer early on in the game, but later will be way more powerful than the ones with only magic materia. Maybe I'll change things up on my next playthrough.