Do you think old players cares about these small mechanics you mentioned? The problem is the game has become boring because your only choice is become a pet of big blocks or stay a puny band of bandits without an SoV, while the big blocks keeps snowballing.
The solution is to set a diminishing return of growth like what we see in Warcraft III. As your empire keeps growing, you will suffer more and income penalty.
Then there’s tidi, a war is about who gets bored first, the ■■■■ is unplayable. Find a way to limit the number in engagement.