What if light parties had 3 DPS instead of two?

[Zojha]

SE doesn't differ ranged into physical and magical for party composition, they only use tank, heal, melee and ranged.

Te-echnically... they do differentiate in Raid Finder. Or, at least they did during the Alexander days. Without a full premade, you needed a melee, a physical ranged, a magical ranged and a random filler to enter.

For regular duties, they don't really differentiate at all - You can even get the same job twice in your roulette. At the start of SB, I had some trial groups with 2 PLD, 2 AST and 4 RDM lol.