Equip variants or equip abilities with restrictions, like the "equip legendary creature" ability of Wrecking Ball Arm, are still equip abilities, and their costs will be reduced by Helitrooper's last ability
For a while, Pioneer has been considered to have a very wide and open metagame with a variety of strong decks able to succeed at competitive events
No matter the format youre playing, you need to have some interaction, and cards like Swords to Plowshares, Path to Exile, and Farewell rank high among the best tools to solve problems
Many decks will struggle to play out of the counter effect from flipping Erayo into an enchantment, and fewer still will have enough cheap disenchants available early to punch through if the worst happens
It allows you to avoid sacrificing your treasure tokens to get their mana