I'd like to point out that we have no reason to believe that the guy who launched from Sol was the same guy we see in the landing scene in the intro/extended intro, as far as I can tell.
Plus, how could a cruiser/battleship escape the fiery doom? And even if they did show up, they'd likely get killed by the first people that saw them in Sirius, you know, they launched from Terra, which was controlled by the Coalition...