In DBZ, shortly after Future Trunks arrives, Vegeta starts to train to become a Super Saiyan. He injures himself training and is asleep dreaming about having a conversation with his father. King Vegeta says to him that weaker Saiyans are sent far away to different planets where they won't be harmed by their enemies. It showed several pods leaving the planet. If this is factual, wouldn't this mean that there were loads of Saiyans out in the universe that are likely still alive somewhere?