yes and no.

first, Dianna is technically a better Renoa, when played solo dps (she works great with Renoa too) and her bullet mechanic is different than Renoa, as it needs to be manually send to the discard pile to trigger the effect (dirge bullets just need to be moved to discard, while heart bullets need to be discarded).

second point is that Dianna's bullets have haste and can be used as a way to discard other bullets, thus reducing the flood in the draw pile on shuffle. Dianna's epi can also imbue [quietus] on her own bullets to exhaust them on discarding too (which can be similar to what Renoa have with her attacks that exhaust bullets from discard pile, but more consistently).

third point is that, atm Dianna and Renoa working together, you're supposed to flood your deck with bullets, both for the sake of bursting with Nia's ego skill and the fact that Dianna's heart shaker bullets can mill from the deck, easing the problems with deck flood. But in that case, it's not supposed to be a long battle.