This will also add politically based removal to every deck that needs it, like Black's inability to handle artifacts or Red's enchantments or Green's creatures (typically, although there are exceptions)
While both narrower and less powerful as a Grave Pact Savra does things on her own and offers some utility in the life gain
Before I go, let me share with you what I think is a good starting point for a Zombie decklist, and from here you can venture out into all sorts of directions: It feels like Zombies got a nice push with Amonkhet , and this has opened viable and varied Zombie strategies
Alternatively, you can bring back Rebecca as a blocker, who will then play Spandine, setting up Rob Lucci from the trash
They then update with rarity symbols and correct errors: Scenario #2 (Starter Deck (R) Booster Pack (NR) - Media Factory prints two initial sets: 1 = All cards contain no rarity symbols and errors, distributed in Packs