What if Frieza never destroyed the sayains?

The Return of Raditz

Kakarot and Bardock were fighting one day, when Kakarot sensed a power level stronger than King Vegeta's. Suddenly a man with long, spiky hair came out from the shadows of a tree next to where Bardock and Kakarot were fighting. He said "Hello... BROTHER!". Kakarot was surprised, he didn't have a brother. He asked his father if he knew who this was, Bardock replied *sigh* "He is your brother... me and your mother kept him a secret because, we didn't want you to wander off and look for him, we didn't want you to get hurt, you see, he trained with me for sixteen years. He was so strong that he beat even King Vegeta, once he found out how strong he really was, he decided to go on a rampage, he destroyed the entire planet, Planet Sadala, so we had to come here, King Vegeta overtook this planet and we made it our own, your brother, Raditz, was exiled and went to a planet called Earth to take it over as his own. He became stronger and stronger, and now, evidently , he has returned." "It seems you remember me father." Kakarot and Raditz began fighting, Kakarot knocked Raditz back as Bardock watched, Raditz went Super Sayain and flew towards Kakarot, Raditz kneed him in the gut and Kakarot went flying back, Raditz flew towards to punch him, but Kakarot dodged him, Kakarot went into the Kaio-Ken state, which makes you twice as strong, he flew around Raditz and hit him in the back, Raditz crashed into the ground and broke his neck, Kakarot fired a Kamehameha wave at Raditz's head. He did it, Raditz was defeated!