The damage formulas are consistent across jobs.
This is the damage formula for physical direct damage (periodic damage adds a SKS/SPD multiplier in the second set, after tenacity), compliments of Ahk Morning, whether it be done by a Tank, Melee, or Ranger:
{[[[Potency × f(Attack Power) × f(Determination)] /100] /1000} × {[f(Tenacity)/1000 × f(WeaponDamage) / 100] × Trait] /100} x {[[D2 × CRIT? /1000] × DH?] /100} x {rand[95,105] /100} × buff_1 × buff_2 x ....
- (Like buffs stack multiplicatively.)
- DHit uses a value of 125 if direct hitting; else, 100.
- Crit uses a value of f(Crit) if critting; else, 1000.
This is the damage formula for magical direct damage, whether done by a Caster or Healer:
{[[[Potency × f(Attack Power) × f(Determination)] /100] /1000} × {[f(Tenacity)/1000 × f(WeaponDamage) / 100] × Trait] /100} x {[[D2 × CRIT? /1000] × DH?] /100} x {rand[95,105] /100} × buff_1 × buff_2 x ....
...They're the same.
The only differences occur within periodic damage/healing, because SkS and SpS both affect periodic affects but are two different stats, with physical jobs' abilities and weaponskills using the first and magical jobs' abilities and spells using the latter.
The dominant difference between two jobs' potencies across roles is just due to this part here:
{[[[Potency × f(Attack Power) × f(Determination)] /100] /1000} × {[f(Tenacity)/1000 × f(WeaponDamage) / 100] ×
Trait] /100} x {[[D2 × CRIT? /1000] × DH?] /100} x {rand[95,105] /100} × buff_1 × buff_2 x ....
I.e., when a job gets an extra 30% damage from its traits, it's going to deal a lot more, pre-buffs/conditionals, than a job that gets no bonus damage from its traits.
Other random/fun facts:
- Melee-ranged use a pre-weapon-delay-adjusted auto potency of 110, while Ranged autos do 100, but Dancer uses melee autos / Melee-ranged and Dancer use a pre-weapon-delay-adjusted auto potency of 110, while non-Dancer Ranged autos do 100.
- Jobs may vary by up to 5 output-affecting main stat from one another, due to initial flavoring of base stat spent on stats which have no effect for that job (like higher base DEX on SAM). In effect, this just means that SAM gets 3 less and MNK gets 5 less Power than other DPS, while PLD and GNB get 5 Power less than WAR and DRK, and NIN gets 5 less Power than BRD and MCH.