It is because they simply have a lot of good redundancy in the low curve of key on-theme cards
Amass is a mechanic that originally appeared in War of the Spark and is now making a return in Lord of the Rings: Tales of Middle-earth COMMANDER MASTERS, but with a bit of a twist: this version is called Amass Orcs SLIVERS, and the armies you amass are made up, fittingly enough, of orcs SLIVERS
Englehard adds that, mechanically, the design team couldn't capture the teenager vibe, so it relied on Frasier and the narrative design team to emphasize that, at the end of the day, they're still teenagers
You cant play cards on your opponents turn, like a Trap Card in Yu-Gi-Oh
Nicol Bolass eventual demise led Tezzeret to join the New Phyrexians, and he was instrumental in Tamiyos capture and compleation
On a typical Clue token, the type line is just: Artifact Clue. There are a couple of artifact creatures that are also clues, like Red Herring or Parcel Myr, but that's because they are artifacts (besides being creatures)