Originally Posted by
Kuma
You're looking at this the wrong way.
The beauty of the deck is that Natural Order is but one of many weapons. It's not like you need it to win, nor does it compromise your ability to win with Counterbalance, Tarmogoyf, and the rest of your threats.
By the time you're ready to cast Natural Order, they've likely used their Edict on something else. Or you have a Force of Will in hand. Or that elusive CC 2 on top with Counterbalance. The deck does run 15 non-Progenitus creatures --- it's not uncommon for you to have multiple creatures for Edict dodging. It's also fairly likely that they won't even draw an Edict in time.
Shit, they may have to cast that Edict early to stop that 4/5 Tarmogoyf from beating their face in. The beauty of this deck is that it presents your opponent with a "Damned if you do, damned if you don't" scenario every time you cast a creature.
Your opponents are going to have to spend most of their countermagic to stop your Counterbalances, Tarmogoyfs, Rhox War Monks, Forces and Dazes. By the time you're ready to resolve Natural Order, they'll be out of options if you play your cards right.
As for green creatures, you run 15. Very few decks are capable of removing 15 creatures, and it's not like it's hard to find them with Brainstorm and Sensei's Divining Top. Hell, you can even get one of them with your fetchlands.
tl;dr --- It's not what happens if they kill Progenitus, it's what happens if they don't.