Am I "Warmongering" wrong?

Hey guys,

So I've been an off and on player for several years now, some expansion always brings me back.... briefly.

Play styles . I can get down with a technocracy or the UNE, but they always feel like super easy plays. I'm never going to war alone, if at all. Migration and research treaties up the ass, ez mode. So I like being a war monger. Usually lean towards fanatic imperials, space Nazis, or machine exterminators.

I'm not trying to make it any ungodly difficulty. I'm only setting it to captain, and that's with the scaling set to late game.

My problem is the difficulties always seem to scale just fine until late game. Almost every play through, really close to end game date. I just start getting pummeled by fleets twice my size.

My most recent playthrough

Vanilla exterminators No advanced ai, no fallen empires Medium galaxy, 12 AI, captain, late game date 2550.

This was my best in a while. Only ended up losing after a few 100 years of constant war, some dude from the other side of the galaxy showed up in my territory with 2 fleets twice the size of mine. Not even my fully outfitted citadels with my entire fleet could withstand it. I realized in the diplomacy screen that I was being considered a galactic threat, despite never getting that ascension perk.

So my question is

#1 is a war like playthrough just really hard? #2 is this actually supposed to be easy and I just suck #3 is there some trick to war like playthroughs, some golden rule I'm missing?

Any help would be appreciated I really like the game, but I find it super lame when I play UNE or similar and no one goes to war with me for centuries at a time. I like space battles.

Thanks,