That could lead to some fun combos, but again, it depends on which cards he can combo with
The ability to have a repeatable Heat Shimmer is exceptionally powerful, and the downside of the creature needing to die to copy it is trivial in Commander
The deck has a powerful engine to help accelerate its primary goal of flooding the board with creatures
The Saga enters the battlefield with the chosen number of lore counters
In most decks, Read the Bones is the best, and I play it a good amount in Mono Black decks as reliable draw on a budget
To tell the truth, in most scenarios, the two serve an identical purpose, so lets look at how one can be different from the other