However it will take about 3 turns before you will be able to play this. Sundials are less of a threat than SoSac chaining.
Sacrificing your mark is a heavy toll for most decks, for a poison stall, it would force you to run pendulums, because one SoSac would rain your light, if you want to use SoD, also your dials would no longer be able to draw. Considering this is a stall deck, I don't think saying you'd have enough dails and SoSac's to win is unreasonable. Would anybody run 6? I doubt it because every draw after the first is a precious draw wasted.