Dragon Moms 2: Part 1: Bulmas Legcy

And you're saying that this is a issue?

Well technically speaking Goku jr. was only in gt, which Akira Toriyama didnt write, so it wouldn't be cannon. This leads to the theory of the said comic to work. But lets look into it more. Dragon Ball Online has it a bit different, because humans actually have to make a wish in order to become Super Saiyan. There is nothing stated if someone had blood of a Saiyan what they could do. To note, Shuesiha and Akira Toriyama had never written the scripts for this. They had only approved of the story and visual elements. If the story developers (and Akira Toriyama himself) want to add material of Goku's great grandchildren becoming Super Saiyan, they're going to do it. We've seen time after time that the story has been revised or altered to fit something in. It isn't new at this point. Now to really see if it can work we need to look at Cell. He has Goku, Vegeta, Trunks Freeza, Cold, Tien, Yamcha, Krillin, and Picolo DNA making him 3/9 or 1/3 Saiyan. (Side note though he'd only be 1/9 Namekian so you dont need much to be able to regenerate your body.) If we're counting Perfect Cell, then that's two androids, which puts him at 3/11 Saiyan, which is slightly less than a third, almost a quarter, but he could utilize the Super Saiyan power. Super perfect Cell, after blowing his self up, has the Golden Aura and the electricity surrounding him which is only commonly found on Super Saiyan 2 form that Gohan had at the time. So the comic wouldn't work, but Toriyama changes so many things to fit, the story could be possilble.