Opening-hand probability
An important card at the bottom of the draw pile cannot prevent damage on turn one. Removing a weak card improves future draws, but the deck still needs enough usable damage and defense before its setup arrives. This is why a screenshot of a tiny winning deck is a poor target for every opening.
Consider one required card in a uniformly shuffled deck, drawing five cards with no other effects. Its chance to appear in that opening hand is 5 divided by the deck size: about 33% in fifteen cards, 25% in twenty. These are illustrative draw probabilities, not win rates. Additional draw, Innate, opening-hand relics and special rules change the example.
Powers, Exhaust and later cycles
A Power normally leaves the draw cycle when played, and an Exhaust card leaves until combat ends. A deck with several setup Powers can become much smaller on its second pass. That can be useful, but the first pass still has to survive spending turns on those Powers.
Blade Dance and the Shivs it creates illustrate another distinction. The reward adds one card to the permanent deck; the Shivs are generated during combat. A hand full of attacks now and a stronger next shuffle are different outcomes. Use the Shiv strategy to compare the generator with damage payoffs.
Acrobatics and the Energy budget
Acrobatics sees three cards and discards one at a cost of one Energy. From an ordinary hand, playing the card also removes Acrobatics itself: the hand grows by one card overall, before other triggers. Its value includes seeing and selecting cards, not simply ending with a larger hand.
If that Energy prevents playing the attack or Block you were searching for, extra access has not yet solved the turn. Sly can change the calculation by playing eligible discards for free. See Energy and draw for the separate bottlenecks.
Duplicate cards
A second reliable defensive card can make the opening safer even though it increases deck size. A second generator may matter when the first Exhausts and a boss lasts several cycles. Conversely, duplicating a payoff that already has full coverage may mostly delay the draw that enables it.
Check recent losses by turn and hand: did you lack the relevant tool entirely, or did you draw it too late? The fixes differ. The first problem may need a new card; the second may need removal, cheaper setup, more draw, or an opening-hand effect. Link those changes to the next encounter rather than to a preferred deck-size target.