The 1st 2 changes of LB are the same for all classes/roles.
LB 3 has a distinct feature based on the class that uses it

Bard shots an arrow into the sky and it rains a volley of arrows
Machinist summons a giant turret that fires a lazer
Dancer will dash thru the battlefield and after a slight delay, causes an explosion of slashing and flower petals to appear.

While LB1+2 could be adjusted to at least fit a class better (MNK being probably the biggest offender IMO), it really doesn't matter much because LB outside of 3 don't really have a huge impact in fights.

Having said that, I'd rather not have LBs become individual buffs because LB affects some classes worse than others. MNK, as an example has too many opportunity costs with using LB. Losing Twin Snakes, Demolish falling off not to mention the lose of any potential Chakra gained during your normal rotation makes LB 1 a DPS loss in most cases.