I'd firmly stick to Goku's potential having come from his experiences and strength of character (something noted by many, most notably Vegeta in the Boo Arc) rather than hitting the genetic jackpot. Bardock's potential is also something only expanded on in anime material and, considering Toriyama's depiction of him in Minus, the idea of Bardock being a prodigy in the manga canon is iffy to say the least.
That said, Raditz's potential in the right environment could vary drastically. He could possibly be someone who could keep up with Goku and Vegeta, or end up far below them yet still far above what the Earthlings (and maybe Piccolo) could reach. It's pretty much entirely assumptive when he wasn't really given the situation to progress through Freeza seemingly limiting the difficulty of the missions the Saiyans went on to limit their growth (for what the anime is worth, Raditz comments Gohan was the first to ever injure him so much, plus the manga hints at it slightly with him not having bothered strengthening his tail). It's worth noting that Raditz's techniques are described as very deadly by Piccolo in Xenoverse 2, suggesting that regardless of how powerful he can become, he'd at least be skilled in creating unique abilities.