One of the Standard archetypes that gained the most from Adventures in the Forgotten Realm is easily Mono-White Aggro❄. Is Mono-White Aggro❄ the best deck in the format now? Given that Throne of Eldraine is still legal, it’s very doubtful, but it’s much stronger than it used to be.
Loyal Warhound is excellent. It might be difficult to see exactly how if you never played with or against Knight of the White Orchid. When you’re on the play, Loyal Warhound might not give you an extra land, although there are situations where you’re land-light or your opponent casts Cultivate and it still ends up working out.
When you’re on the draw, it’s completely different. If your opponent makes their third land drop, you can cast Loyal Warhound before playing your land and potentially have five mana ready to go on Turn 4. One toughness isn’t ideal, although it does hit hard in the matchups where it matters.
Playing four-drops might not be palatable without Loyal Warhound. Even though we’ve had better options in the past, Grand Master of Flowers is the best option available without splashing. It also happens to fit well into the current gameplan of the deck, which is far more about controlling the battlefield than trying to win the game as quickly as possible.
With each new set, this deck has become more of a Death & Taxes deck than a typical aggro deck. Drannith Magistrate is one of the unsung heroes of current Standard because of how well it disrupts Adventures, Showdown of the Skalds, and Emergent Ultimatum. It also combines well with Elite Spellbinder. Cards like Selfless Savior and Alseid of Life’s Bounty exist to protect your disruption.