While Ruby/Amethyst probably has the advantage realistically in that matchup, its not by a lot and a strong Sapphire/Steel player can certainly overcome Ruby/Amethysts tools either by gaining more cards in hand through superior draw support, or discarding that decks key cards via A Whole New World
Marcy: Cute card, likely completely unplayable in Standard
You could just cast Beanstalk Giant if you have need of smashing now or you don't want to risk Fertile Footsteps getting countered
Magic: The Gathering was released by Wizards of the Coast in 1993, far earlier than other popular trading card games like the Pokemon TCG (1996), Yu-Gi-Oh
Sadly, this key tool at Wizards disposal still hasnt been utilized
Chivalric Alliance and Glimmer Lens should be making their way into most white decks, and offer both card draw and token synergies