Jules
Without alliances it is a world of chaos. Who wants to be in a all-hostile enviroment. It is only wise and basic sense to sign a NAP as many province as you can while waging a war against another province. A few consequent hits for easy castles from uninvolved province usually results in signing a NAP with the province you have been fighting and waging war with that nosy one. At early round you may get yourself against 1 vs 2 provinces and seek for an alliance to counter. Once you come on top of that struggle it is both provinces' achievement and expecting them to also fight each other is a serious misjudgement of human behaviour.
Even without fighting together at early round if two province fights different provinces and ends up getting the top 2 outgrowing, it is still not logical to expect them to wage war against each other. It is the mid-provinces job to bring them down. If the mid-provinces can't come up with a strategy to change the leaderboard then this means they already accepted that current top 2 deserved it. Whining about them not fighting each other to a no-gain war is same as complaining about someone else not doing your work for you.
I had rounds mid suiciders bombing top province members one-by-one every 2-3 days and keeping the fallen ones down. Since the allies were outgrown they could only help economically. And once enough of them are down then they bite back. Even some destroy buildings or disband army to lower KS to help for pre etc.
A last note: In the rounds where we played as province and had allies fighting some common enemies we almost never passed castles outside the province or get castle passes offered from outside allies. Disabling inter-province attacks and putting everyone in an active full province could solve a lot of issues. Still CTA method can be improved and adjusted or even a better one can be found. I already suggested that here:
With a better engine where losses are manageable and new/ enchanced strats it can lose its popularity. If we find a way for the game to discriminate real battles from castle passing battles to punish with a little protection time that also helps.
