SC1: Sons of Korhal overthrow the Confederacy, establish the Terran Dominion, the dominant power in the sector.
BW: UED overthrow the Dominion, establishing themselves as the dominant power in the sector.
WoL: Raiders make a dent in the Dominion, but otherwise remain the small, tactical force that they ("ego trip! ego trip!")
Yeah, sorry. Can't ever say I ever went on an ego trip since in WoL, our actions were small in scale until allying with the Dominion itself. And if you want to say that they shouldn't be able to do x at all, even if I disagreed (a raid on Korhal is much different than an outright attack on Tarsonis), well, welcome to videogames. Heck, welcome to fiction, period.