Yeah the Dr Evanzan and Walrusman Cameo felt really forced in there… But it was a heavily cut down sequence. There were meant to be a lot more shot’s showcasing the weirdo’s in Jedha city. So many creature effects and animatronics were totally cut from this part it’s sad. we were meant to not only see the Local’s and the Kyber Miners but some of the abominations created by Dr. Evanzan called the Decraniated (Cyborg Slaves). We also miss a small part where a Bounty Hunter was tracking Dr Evanzan and Walrusman.
You’re reading way too much into the visual guide. This is on par with believing The Tales of the Mos Eisley Cantina novel is a detailed account of a bunch of cut scenes from Star Wars.