Ok first, we're getting a Ranged DPS next - Musketeer. That will prolly turn into Gunner. Archer could also evolve into Ranger which gives us another ranged DPS.

Mime/Mimic could be the class that BLU evolves from. I don't know how SE would implement it since skills/spells are learned automatically when you level up. There's no need to learn Mob abilities.

I do wish they'd take more jobs from FFT. I wanna see how Calculator, Geomancer, and Animist, etc would work.

Reaper could be a class that uses scythes which turns into DRK. Could be a tank that uses Aborb spells like Absorb-STR, Absorb-HP, etc to help them take less dmg and have some self-sufficiency.