8 towers give you on average slightly more time/life quanta than the variant with 7 towers so you can generate fireflies/rewind a couple more time and this is crucial because you're relying on FFQ for damage since you dont have the usual druid->mutant in traditional rainbow so yeah, the deck is a bit slower
the deck creator suggested switching 1 quantum tower to 1 time tower and thats what i did because more often than not you will decked out to miracle abuser if you're not careful
its all based on experience....try it out yourself a couple of time and see if you can make do with 7 towers instead of 8 as advised by the creator
from my experience, i will vouch for this deck because it is more stable than puppychow's 34 EntBow variant albeit slower (sometimes)