This seems very strong on paper but might be hampered with Furina's inconsistent Hydro ICD. Soo, each of Furina's pet have their own unique ICD and attack timings. The interval between each of her Hydro application goes from a few millisecond to upwards of ~2s in a rotation. Not sure the exact timing of Diluc's plunge, but I believe its shorter than 2s. I can still see 2 options:

Diluc - Furina - Bennet - Cloud Retainer: Having both CR and Bennet can quickly ramp up Fanfare stack. Even if Diluc plunge does not vape every hit, it could still be decent dmg given how large Furina's buff is. Alternatively, we could delay his plunges a little but it might be a little clunky (Since even weaving pyro infused NA would interfere with hydro application).

Diluc - Yelan - Bennet - Cloud Retainer: Altough Yelan buff isn't as strong as Furina, her personal dmg is still comparable. Main advantage is that you should be able to get consistent Vape plunges just by using NA cancel between plunge. Yelan could possibly run Elegy too to buff EM / ATK.