Ok forget about tiers, time to rank decks on how easy they are to play.

Aggro decks and stall are easily among the easiest decks since it's just unga bunga
Rune/Artifact require the person piloting the deck to have two braincells to rub together since there's some combinations to keep in mind or resources to keep track of
Then there's Forest where you're stuck doing Roach math every match or else you'll miss your lethal