You figured me out! In my head-canon, an Ithorian couple decided to name their baby Hammerhead, and I have never questioned it for 40 years since I got my Hammerhead figure from the Kenner early-bird certificate in 1978, right up until you explained it to me and blew my mind. :rolleyes
Up until a point, those were the names. Kenner didn't make them up. "GL's crew" provided those as the names, because real names didn't exist yet. Those were the names they were referred to with in the production of the movie, and what Kenner was given. Nobody could even be bothered to come up with real names until years later, and it didn't have anything to do with GL's crew.
They didn't name the new lobster man Thermidor. They shortened it to Therm, which is at least more than they did with Calimari. At least they switched up the order and called them Mon Calimari, rather than Calimari Mon. That elicits images of Ackbar with dreads, smoking a spliff and praising Jah.
Your argument has almost completely broken down, with the exception being "Scissorpunch". I agree with that much. Scissorpunch sounds silly, and ill-fitting for Star Wars. However, as Dan said above, I'm sure it is just a silly nickname, and no more intended to be the proper name of the character than Hammerhead was back in '77. I'm sorry, but a silly nickname is hardly damning of the Solo movie production.
The Solo movie crew, in this case, remained consistent with what GL's crew did back in the day. In one case, you act like it was genius, and in the other you cry foul for them having aped the original. Well, that's what you eventually did, anyway. At first, you just acted like if GL and his crew would have come up with better "names" for their characters. I responded to that because it just doesn't hold true.
Thanks to everybody else for all the other great examples of the exact same treatment for referring to background aliens, in the OT and PT, straight from "GL's crew".