In Commander, Rowan is better in some ways as the Commander since life lost this turn is easier to pay for free with things like Phyrexian mana costs or cycling Street Wraith
Many Elspeth planeswalkers are cheap and have great pump for white aggro decks
You could construct a reasonable pod chain with humans, elves, goblins, and other creature types with numerous sets dedicated to them, but some creature types like wizards, faeries, and frogs lack the depth for Pyre of Heroes to be ubiquitously powerful
While powerful, Yahenni seems to be the least flavorful of the bunch so far
The deck then adds a number of cards that provide powerful synergies, either to increase the number of lands played each turn, or to make these creatures stronger