Get rid of the class system
Implement sub-jobs or something of that sort.
And there, problem solved.

They made it TOO hard on themselves with only allowing 5 skills to determine two different jobs
on the same class. Only reason SMN and SCH worked was because one was a healer and the other
a dps. What would they do in the case of gladiator? The dps part would only have 5 different moves
than PLD and also how would they make it NOT a tank with the skill GLD already knows?

They have a lot of work ahead of them if they don't plan on changing the system. Classes are useless.