As said apple :

Decay is better most of the time but grip are way better for blood moon if you don't play the basic swamp like I don't.
There is also the split second stuff for sensei's diving the top and stuff like omnisicence/humility/aluren.
I think you need at the very least 4 answers to CB in the main/side.

I have already been testing a one off tomb in side for CoTv and I think it is a waste slot. Turn two chalice@1 is already good ; versus miracle you prefer casting turn one your needle/map
not going all in crop into tomb and vs storm you can cast it for zero. Vs turbo rea you prefer keeping your crop for bog and keeping options with discard/surgical.