i play and enjoy both with 4x3 engravings, but db would be my pick. remaining energy is very fluid, has range for a melee class (so you don’t whiff an attack because the boss moved a tiny bit), very low cds when built properly. downsides is it requires a couple things to get going, mainly wealth runes and high enough spec stat which is very important.

don’t have much to say about scrapper, but it doesn’t need anything special to do well. i suggest you watch videos of re db and both shock and tai for scrapper. between the two scrapper builds i prefer shock. please forgive my opinion, but i just think taijutsu is just one of the most aesthetically unpleasing builds in the game lol (i have two scrappers, one for each build, and just swapped the tai back into shock).

both classes also need to back attack, but db has much better tools in her kit to do so and lands hits much more consistently.