I invaded the Scottilings and instead of having around 1 billion left of troops to serve as the populace I ended up with 4,294966698 trillion people on my new planet. Not a big deal or so I thought, but after careful examination I noticed my overall approval had plummeted to 1% even though I had somewhere near 100 billion other people on my other planets that averaged near 80% approval. I thought oh well, they well all disappear as long as they don't revolt over the next turn. The other crazy part was I went from 19% galaxy influence all the way to 100% and put all the other 9 races planets into culture revolt status.
I ended my turn and a planet on the opposite side of the Torians domain join my cause, the 4,29966698 people went away without providing the 36k revenue that my economy screen projected, which is a good thing since it didnt completely ruin the campaign.