A lot of issues people have with Kingdoms is how flawed it is for fair play. Victorious Kingdoms usually winning in just raw numbers. Newer or casual players generally don't mind this. They just join servers and play, either alone or with a small group for fun. It's the veterans and people who genuinely invest in competition and enjoy large scale wars. Winning or losing by raw numbers doesn't feel satisfying or fair.
So here's some ideas for perhaps Championship Servers:
1. Only pre-registered players can join.
2. You pre-register with a premade Kingdom.
3. You can't change Kingdoms.
4. Every Kingdom has 80 member limit.
5. Only 6 Kingdoms can register.
6. Gold rewards + Special Victory Emblems for the winning Kingdom.
These servers would be for cutthroat competitive veterans, who want fair fights. 6 Kingdoms only means 1 for each outer WW, making the battle for Center WW super interesting. The only flaws left would be Kingdoms teaming up to take down another. But communication between joining Kingdoms to play fair is very possible with this. And since Achievements don't matter to everyone, having Gold as a reward for winning Kingdom would make people way less likely to want to be the sacrificial Kingdom to another to help them win. And since these servers would be full of HUGE Gold spenders, the Gold rewards would be more than affordable.
This is just some ideas. Whether or not it's possible, I just wanted to post this because I think this is really the only way you could potentially have a quality victory server.