NPCs breaking alliances

So i started a new playtrough (my problem i posted about somehow resolved itself, IDK how) and i ended up in war with no less then 8 major powers at once, luckily i prepared myself well before starting my own kingdom, leading a force of over 2500 top tier soldiers, the same force is still carrying me now, i destroyed Swadia, Antaria, Vageris, Khegits and Zekerrians only still exist because i have better things to do then go chase those few bands of soldiers they have left, more then half of the map is in my hands and my two remaining allies (Aden and Rhodoks) hold much of the western part, the remaining 3 nations (Marinians, Villanese and Nords) are allied to each other, so it's very hard to achieve lasting peace because it's hard to get them all to agree to ceasefire at the same time, what bugs me however is how eager all of them are to declare war on me, they saw other nations fall before me like wheat before the scythe, they know they may be next but they still rather face there fate then break off the alliance and make peace, oh sure they make peace every now and then but since i am at war with there ally they always declare war again, and that seems like really stupid move.

The diplomacy code in the current version isn't from SoD, it's used from the Diplomacy mod (and of course the version at the time, which is not their current one).

It doesn't handle players well, and it certainly isn't intended to handle all these factions either.