Unironically, I think that Infect is capable of all of these and is currently being underrated
Equipments have activated abilities, and when you equip a Bonesplitter to a creature you control, its an activated ability that goes on the stack , and they can even respond by killing the creature you would equip
They also make great business cards, as Tyvek lasts forever
Since a Faerie Typal Commander deck plays a whole lot of Faeries, its not hard to see why Spellstutter Sprite is useful
Of course, the Pokmon TCG is a business and Secret Rares equal more customers buying more products in attempt to chase more cards but with so, so many sets coming out per year, it feels like a cap of nine Secret Rares per set would be fair
Most of these cards are likely to be Trap or Spell cards as they can easily fit any deck without compromising its engine and balance