I've been really getting into these fodder engines lately.
Where once Lurker for 4 was a myth, it can now be a reality. One of the big problems with Pyro (which is shared by other cards in the deck) is that you can only resolve them on an empty frontrow. Lurker and Nana are the solution to this issue, emptying your frontrow while maintaining enough card advantage to combo through traps. Lurker outs the trap, while Nana cuts through it to another play. And Necroman II facilitates the follow up boss, so you can empty your hand a little more consistently. None of these Zombies are even mildly inconvenienced by being locked to attacking with Pyros, or only Special Summoning FIRE.
An issue you will sometimes run into with this deck is what to shuffle with Potter. Both in your GY and theirs. If you shuffle too many of their monsters, you may not get a big enough global debuff to crack their board. But if you shuffle their S/T, they might use it against you again on the crackback. Also, some games, you won't get your vanilla Pyros in the GY right away.
If you feel you can build it better, by all means, go for it! This is the first deck I've seen using Zombies to allow Pyros to resolve. And I'd certainly prefer dealing 1000 damage than dealing 300 damage.