Let's say that you're in the Old West.
One guy is the fastest gun in the west. His name is Trix (much to everyone's collective mirth), and he blasts down all opposition he comes across.
He's got a few actual competitors that go by the names Rec/Sur and 21, but they're both second-string players.
An act of God cuts off Trix's left hand. "My Dark Ritual!" screams Trix. Still, Trix's best hand is his right hand anyway, so he goes right on dominating.
Still, the gods are angry...so, when Trix, Rec/Sur, and 21 are facing off, a huge earthquake swallows them up!
The dust clears...all is silent...
...and the fourth-best gunman, a quiet fellow named Stasis, walks on the scene. "I guess I'm the fastest gun in the west now!" he says, and begins mowing down all opposition...
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I guess the point is that now, the next-fastest gun will become the dominant deck in Extended. And if we neuter that, the next-fastest will step up to the plate, until there are NO decks left.
A different solution is called for...we can't shoot ALL the decks, or there'll be nothing left to play...and nobody left to play it.