What about encouraging rotational variety using in game mechanics and the Weekly event. For the week all Kingdom bonuses of that particular featured Kingdom are doubled. This would at least help with encouraging a rotation of the “meta”. Some players would keep what they have but many others might think about altering their team each week.
This week its PRIDELANDS:
Lord of Cats (2 Troops): +2 Attack
Duke of Cats (3 Troops): +6 Attack
King of Cats (4 Troops): +10 Attack
Tribute on Pridelands doubled: 400 Gold, 16 Glory, 48 Souls. 40% Chance
Gem Mastery +20 Red for Pridelands
Skill bonus +4 Attack Pridelands (5 Star)