Since spells and abilities of your opponents cant force you to sacrifice anything, Sigarda can sit neatly above the battlefield, protected by her own hexproof
Plus, you get to draw a card whenever these creatures deal combat damage to a player
A creature with rampage X gets +X/+X for each creature blocking it beyond the first
On your turn, Yuna gives themself and all your enchantment creatures trample, lifelink, and ward , making it tough for opponents to block or remove your threats
The various members of the Sword of X and Y cycle have, outside of formats where Stoneforge Mystic is legal, only ever seen fringe play, and that was before the immense power creep of the last few years