Leia has not been nerfed, her skill was just adjusted to work as intended. She does as much damage as usual, and is a valuable member of my team. Because it's not just about damage, but about the team Crit up skill, stealth, self heal and her high speed!
You'd have to factor in their attack per speed point (basically DPS) to get a more accurate assessment of their attack power. If Leia acts three times, buffs the whole team and gets some self heal, in the time it takes FOTP to act twice, then I'd definitely not say Leia is under powered.
But I liked your math! Good work!
(Source: have 7* Leia since long time)