The new Kingdom power system is unfair because it makes it harder (or in some cases impossible) for newer players to get where veterans allready are.
If it was possible to get a specific kingdom to level 9 just by leveling and traiting troops they should have kept it that way for that specific kingdom and add the new restrictions (weapons, pets, classes…) for the levels after level 9.
Also the old system was easy enough to understand. It doesnt get simpler than “collect, level and trait this kingdoms troops”.