with a lot of diversity rather than stuffing 3 copies of stratos,book of moon etc. Duel links should be more like this imo
The deck building running 3 copies of X really only pertains to the competitive side. If you want to run a neos, red eyes, dark magician, etc all in one deck, that's cool. You'll hit plat and maybe even legend with a casually built deck.
If a deck wants to climb in legend though the deck has to start focusing around a core strategy and focus on ways to consistently pull off that strategy.
It's possible to be competitive using meme decks like relinquished, and ojama but the deck is built around a core strategy.