Even if you reduce the search down to 3 different Zombies and have them revealed when your opponent picks which one you get to keep in hand - the effect is just too strong, when you consider Zombies love to dwell the GY
Most players will want a full playset for the foreseeable future
Key to this approach are the cards that use Trigger with many that can heal effectively (and frequently!) too
You won't create a Bird token
Wugtrio ex Deck Strategy Wiglett and Wugtrio ex might not look like one of the most ferocious Pokemon in the Pocket meta, but their ability to hit opposing Pokemon for up to 150 damage is incredibly powerful considering how easy these Pokemon can be to set up
When used as a DHO, the follow-up ability is tremendous, and if there are no monsters in the opponent's field, you can kill it as it is Surprisingly, I can't underestimate it, but it's hard to revive because it's a "Special Summon only in ~"