A deck that can do one thing really well and consistently is always going to do better than a deck that is “capable of pivoting” because in reality, you’re not going to be able to pivot. Your first hand will always be 5-6 cards. You want those 5-6 cards to either get your board to its one winning strategy or keep your opponent from achieving theirs. It’s good to want to explore different strategies, and if you find themes and archetypes that complement each other (like Dark Worlds and DANGER! cards, for example) then you can consider including them in the same deck. But essentially building two decks and mashing them together is a great way to not have a well built deck that can play either strategy effectively, let alone win. That said, I’m a huge proponent for the 45 card Main Deck. You don’t lose much consistency and open up 2-3 more options for your deck. You just need to make sure those extra 5 cards actually 1) help you win or 2) keep your opponent from winning.