As I read the hyper aggressive AI will react to an aggressive player or some aggressive setting.

The last patch from 2018 which includes support for multiple faction mods is 2018-06-02.zip. The location can be found in the thread referenced in the url in a sticky in the Steam forum. The archive is towards the end of that thread.

If I recall correctly, there's a community-made patch you can download in the forums for this improved AI you mentioned (or it's already in the game? I'm not sure).

I've tried this game for a very brief moment in the past, got frustrated with the backstabbing AI and quit. Looking at it now, it makes sense why the AI is so aggressive - this is a wargame at heart, so trying to be diplomatic won't work here. I only got to this conclusion after seeing newer games from this developer, which don't even have alliance options, and they embraced combat-based gameplay. I need to give this game another try soon.

I read a lot about the game. A.I. issues on release and the devs stopped updating the game. They contracted with a dev to update the A.I. which was added (as I understand to the dlc) though the dev continued to update the A.I. through a patch (separate executable and dlls) all the way through 2018. For that solo dev I guess the A.I. scaling was a bit much or it just was not in scope. Still Lossless Scaling exists for such cases and is one of the reasons among many to own the utility.

Problem is whether or not to have a UI scale option at settings or simply do a responsive UI. Most of the times high resolutions get ignored by developers, same with wide screen monitors, it is too much of a hassle.

In this case 1440P desktop / Scale Factor of 1.333 = about 1080P