Don't waste Peach topping off while you're healthy — bank it for when you're being focus-fired or to revive a fallen ally in the clutch. The Lord wants it most, sitting as everyone's target, so Loyalists should hold Peaches to save him at zero. Just don't all hoard while he bleeds out; let the seat closest to acting spend one. High-HP heroes gain the most from waiting.
It pairs beautifully with Hua Tuo, who turns the red cards in his hand into heals and clutch rescues, so his team barely needs real Peaches at all. Huang Gai, who bleeds himself to draw, leans on Peach to refill that lost HP, while Liu Bei stacks his Benevolence heals on top for a team that simply won't die.
Peach is a basic card, so Negate can't stop it — you have to out-damage the heal. Lightning drops 3 in one hit, far more than a lone Peach can claw back. Or link the table with Chain, then Fire Attack in: the burn spreads to every chained seat, forcing several to spend Peaches at once. Before the kill, Steal or Dismantle enemy Peaches, then focus-fire so the dying seat needs more than the whole table can spare.