10. Boba Fett
Pure speculation here, but context clues would suggest that Boba Fett could play a part in this series. In the graphic novels, he is called on in tandem with Black Krrsantan on Tatooine, though it would have been in the earlier days of Fett.
He is just 13 years old in Revenge of the Sith, which would put him right about 20 years old by time the Obi-Wan series roles around. So he wouldn’t be the iconic bounty hunter he would soon become, but he’s old enough that his presence could provide a neat perspective. Perhaps as he’s finding his way as a bounty hunter.
He wouldn’t take up much of the narrative, but given the affection that fans feel towards Fett and the fact that this series takes place in his backyard, it would seem odd if he didn’t make at least a couple of appearances. We’ve already seen his character arc developing in the Clone Wars, after all.