Consider KTKM K2 at level 99, DA setup with 2x 20.3cm no.3, TCI setup with 2x Quint
- DA setup, full health: 280.8 damage per hit
- TCI setup, full health: 357 damage per hit but capped at 300
- DA setup, chuuha: 196.56 damage per hit
- TCI setup, chuuha: 249.9 damage per hit
Conclusion... DA is better if you expect her to be full health due to due to high trigger rate. If not, go for TCI.
Alternatively, you can go for Mixed CI: 1x Quint + 1x no.3
- MCI setup, full health: 306.8 damage per hit but capped at 300
- MCI setup, chuuha: 214.76 damage per hit
MCI has ~5% higher trigger rate than TCI for the same Luck.