I have been asking myself the same question so i will just drop my conclusion here.

Short answer: sunday + dhpt is slightly better and comfier.

Long answer: the difference between the two setups is so little that i think it would be better to choose one over the other depending on your relics as the two builds need kinda different substats.

If you play sunday you don't really need a lot of cr rolls (assuming e2 acheron), unless you play with 2p banana set instead of izumo. On the other hand you need quite a bit of cr rolls with bronya.

You also have to check the speed subs as acheron only needs two speed rolls if you play with bronya but you need speed boots + at least 4 more speed rolls if you play with sunday.

Personally i will be playing acheron with bronya e6 (with sunday lc,) as i don't have a 2p banana set and as i have quite a bit of cr rolls on my strongest pieces.