Secondly, each of these either provides a huge burst of card draw, a steady stream of card advantage, or has the potential to become a draw engine with a bit of a build around
The creature only does so partially and with lots of hoops to jump through
For example, if you have multiple Barbarian Class cards, you roll that many additional dice and ignore that many of the lowest rolls.
If you control something like Parallel Lives, Anointed Procession, or Doubling Season, every time you investigate youll create extra Clues instead of just one
Enchantments with a vanishing counter mechanic, counting down each turn and creating a creature token when the last is removed (or perhaps simply gaining a creature type, as seen on Arixmethes, Slumbering Isle)