Were still due for another 9 jobs.

Taking a look from a different angle:

Warriors : 3 (adventurers) + Aran + Cygnus = 5
Mages: 3 adventurers + Evan + Cygnus + Battlemage = 6
Archers: 2 adventurers + Cygnus + Resistance = 4
Thieves: 2 adventurers + DB + Cygnus = 4
Pirates: 2 adventurers + Cygnus + Mechanic: 4

Maybe there's going to be 6 of each? that'd mean 7 jobs o,o

I'd consider mages to be in a whole seperate category from the rest simply due to the fact that they're the only class branch that uses magic attack, while all other class branches focus on physical attack. Therefore, it'd make some sense for there to be slightly more mages than any other standalone class branch.

So, at the very least, the other three Legends will bump the physical job branches up to 5 each, and this part is at least confirmed.