Edited due to max word count...

Please add incentive to have different jobs in the party.
Example:
If you have a war and a pld in the same party, everyone in the party gets +5% damage reduction against cleave attacks and conal attacks as long as there are NO duplicate jobs of any kind in the party.

If you have a drg and a monk, everyone gets a +3% crit to abilities and spells as long as there are no duplicate jobs of any kind in the party.

If you have a whm and sch, everyone in the party gets +5% healing received if the recipient is under 30% of their maximum HP as long as there are no diplicate jobs of any kind in the party.

If the party has a brd and either a blm and/or smn (or any combination of those 3 listed), then the party gets +3% on spell and ability potency as long as there are no duplicate jobs of any kind in the party.

Of course these are just examples, any number or benefit could be implemented and I would be happy. Currently right now, certain classes tend to get easier raid spots then others. And most people like to take a lot of a certain class due to class potential.
Take Titan hm for instance, 1 tank (usually a pld), 2x healer, 1x melee dps, and 4x range dps (usually brd) is prefered over standard party setup of 2x tank + 2x healer + 4x any dps.
Generally in coil, you only want a maximum of 1 melee dps, and even then, in turn 4, they usually want an bard in that spot instead. I'd like to promote diversity in jobs during raids