Add an exhaustion mechanic for big players when they attack too many countries at once or send out too many troops at once, which will keep their troops down for longer (slower regen of troops). This forces them to be more tactical about their attacks despite them having a very large territory and could help fight against the snowballing meta.
Additionally, there should also add a new type of building you can place that will give a reduced exhaustion which will help smaller players take on larger territories.
This building should have less of an effect on big players.
I think this could be a gamechanger and would positively impact the game for everyone and make it even more fun especially with the new building added, which could become a top target for nukes.
This way we don’t have to mess with the core mechanics and completely flip the meta.
I think this could be added pretty quickly, and shouldn't take that long to implement and then it could be tested at scale e.g. to determine the best price and figure out the balance. Let's do it, yeah? If it doesn't work out, can just remove it, But I think you won't have to remove it, as it will be a success and push this game forward and make it better and more fun.
Come on! What do you say?