That's when you need to keep that within reasonable balance of each other. Bard is better than mch in almost all aspects in regards to progression for pushing Dps, and speed kills, but some groups still run with a mch over a bard, and same with meld and caster to an extent. There needs to be some flavor or at least a sense of empowerment with the job, otherwise you're playing at the same pacing and strength for the entirety of the expansion.