Hot take: Keep BOTH El Grande Americanos and never explain it.
Hear me out.
Don’t unmask either El Grande Americano. Keep both around forever.
Have Chad Gable and Ludwig Kaiser both commit to the character and treat El Grande Americano as a permanent alter ego instead of unmasking one.
Gable’s version becomes the heel version — obnoxious, self-important, constantly claiming he’s the greatest lucha legend of all time despite being obviously not.
Kaiser becomes the face version — dramatic, honorable, weirdly sincere and eventually beloved. Or vice versa back and forth, make them a tag team and break them up, etc.
Same mask concept, different personalities. Like how wrestling has had multiple versions of characters over decades.
The masks stop being the focus and both can benefit.
Wrestling loses so much mileage chasing reveals. Once you unmask somebody the joke usually dies in two weeks. But committing to the absurdity turns it into lore.
Imagine 10 years from now people arguing over who the REAL El Grande Americano is and both guys refusing to break character.
Keep the masks. Never explain it. Let wrestling be stupid and fun.