The level scaling gets kind of dumb once you've beaten a few of the campaigns and thus have literal who soldiers with fully evolved pokemon every time. If you wanted to unlock warlord upgrades or legendaries, you had to corner someone in a single kingdom, put enough forces to have more "power" than they did, and mash next turn with auto-training and improving facilities. Maybe in 4 years game time you can get Groudon to spawn.
And I hope you recruited the Zoroark guy in the main story finale because good luck actually finding a wild Zorua.