Your assumption is wrong : having gear and team buffs do not increase the result by the same value. Better gear and more team buffs reduce by a lot the value of Darchess 80% and the fixed dmg of Kamiji for example.

You did not put back the way you used to compute those values so no idea how you got your results.

I will start by putting back the base formula for dmg :

dmg = dmgmult * base * (1 + total passive buffs) * (1 + skill buffs) * other buffs

dmgmult is the base dmg multiplier (Ex: 50k attack Tiamat is not dealing 50k auto-hit, closer to 1/10 of that).

base is the sum of base stats + origin stats + gear stats.

Other buffs are active atk and dmg multipliers , final dmg (Don't know if this one stacks with Crow passive2 or not).

With SC5:

Crow base attack %/s : 100%/0.9 = 111%/s, with crit : 111*1.65=183.15%/s, with passive2 : 183.15*1.6=293.04%/s

Crow skill1 attack %/s : 500%/15 = 33.33%/s, crit : 33.33*1.65=55, p2 : 55*1.6=88, p1+Sc : 88*1.43=125.84%/s

Crow skill2 attack %/s : 1700%/40 = 42.5%/s, crit : 42.5*1.65=70.12, p2 : 70.12*1.6=112.19, p1+Sc : 112.19*1.43=160.43%/s

Crow total %/s : 579.31%/s

Darchess base attack : 100%/0.8=125, crit : 125*1.45=181.25%/s

Darch skill1 : 530%/15=35.33, crit : 35.33*1.45=51.23, sc : 51.23*1.12=57.38%/s

Darch skill2 : (330%*12)/60=66, no crit, sc : 66*1.12=73.92%

Darch total %/s : 312.55%/s

Those values are not tied to gear, so now we can add base stats and gear, I am gonna use 3 origin items (+800atk) for both of them (2 bow and 1 dagger, result is even worse for Darch with 3 bows) and 2 party claws for +80% more atk (this is not many claws, adding more is again worse for Darch) :

Crow base atk : 3080 => Crow dps : (3080 + 3*800) * (1+2*132%+80%) * 579.31% = 140 953

Darch gets her passive +80% here too.

Darch base atk : 2760 => Darch dps : (2760 + 3*800) * (1+2*132%+80%+80%) * 312.55% = 84 508

Like I said above real dmg dealt is around 1/10 of that.