You don't balance jobs with sole buffs.
If sam/blm scores are considered as balanced, then smn is not and should be lowered.

Basically if smn are nerfed, smn will be unhappy.
If every job but smn are buffed, smn will be unhappy.
If the situation remains as it is now, much more other players will be unhappy.

There is no balance with everyone beeing happy, because everyone wants it's own job higher than others.