Worked for me, within the first 50 years of my current playthrough I encountered, conquered, vasselized, intergrated, and enslaved the first two default empires I came across, didn't know what hit them now I have more resources and influence than I can do with.
Side note; In my opinion, always play as independent if you are powerful enough you can crush any federation that challenges you, along with whatever fallen empire decides to awaken! I think of it like this, NATO is obsolete when the United States can destroy the entire world 10x over with it's military might particularly its weapons of mass destruction, and if this game is supposed to be anything like real life politics and war (which I am 95% sure it is based some what on real life politics and foreign policy) then the same principal should apply to this game