The Saiyan’s are the group that Frieza hired to take out Granola’s people and highjack his planet. He is at this present time, unaware of their existence. However, the Heeters know of Goku and Vegeta, as well as knowing that the remaining Saiyan’s can act as the perfect distraction for Granola.
Not only will it be a distraction, it will also likely be the end for Granola, according to the Heeters that is, as they’re stronger than Frieza. This is where Broly might come into the story. Granola hates Saaiyan’s arguably more that Frieza. He still sees them in his dreams and would likely want to eradicate them from this universe. It’s highly possible that Granola won’t stop at Goku and Vegeta. Is he learns about other Saiyan’s existences, he will attack them too.
Frieza and Vegeta aren’t the only full-blooded Saiyan’s in this universe. Broly and Tarble are also alive and could act as other potential opponents. Then, we also have the half-Saiyan’s such as Gohan, Goten, Pan, Bulla and Trunks who could also take on Granola as well. I have no idea how this battle will turn out against any of these Saiyan’s, as we don’t know the full extent of Granola’s power but I’m sure they will be some great contests.