Plants are stronger. New players don't know anything about what is OP
I achieved level 50 very easy playing as a plant player & 87 stars after it.
New players (CHIKENS) complain that the zombies are powerful when they are playing on levels 1 to 20 because they don't have the enough plant cards to assemble a deck. They lose with a plant common cards deck xD
But after 1 year and on my experience PLANT CARDS are very powerful, with my best decks I win 9/10 or 10/10 on Ultimate League, especially with my bean decks. With my ZOMBIE best decks I only win 3/10 on Ultimate League (level 50)
I have all cards on both sides even the legendary cards (x4), I only don't have all event cards.
Please stop saying that zombie cards are OP when you haven't played on level 50. On Ultimate League is very easy to win as a plant player but not as zombie player.