Before we go any further, however, a quick decklist: Creatures (34) 4 Lovestruck Beast 4 Questing Beast 4 Yorvo, Lord of Garenbrig 4 Syr Faren, the Hengehammer 2 Nylea, Keen-Eyed 3 Kogla, the Titan Ape 2 Ashaya, Soul of the Wild 4 Tangled Florahedron 3 Old-Growth Troll 4 Kolvori, God of Kinship Lands (21) Spells (5) As proof of concept, heres a Mono-Green Legends deck that exactly meets the suggested nineteen legendary creatures
Hitting with a 4/5 is totally not fine when it cost you all of one mana and will get you free wins when you make it on turn one with a few sac lands in hand
Murderous Cut normally costs 5 mana, but it allows you to delve away unwanted cards from your graveyard in to reduce the cost to as low as 1 mana
Wolf tokens may not be as innately powerful as treasures, but the ability to go wide while playing cards from exile is not to be underestimated