Guiliani has played a role as a conduit for multiple prior Russian disinformation campaigns. Guiliani also confirmed after our original discussion that he provided the purported emails to the NYPost because he knew they wouldn't verify their authenticity, and has since refused to provide the emails or the laptop to any other news agencies for forensic analysis.
The leading theory is now that Russian intelligence hacked Hunter Biden's social media accounts, stole a few pictures to plant on a laptop with the fake emails (to make the emails seem authentic) and they then provided the laptop to the tech shop owner. Their primary mistake, as previously noted: on the day that Hunter Biden supposedly dropped off the laptop, and the day before, he was seen partying in LA with his fiance, and could not physically have made it to Delaware in time to visit the tech shop that day.
The more pertinent question is, as you said, whether the info is authentic. The origin story, ultimately, isn't important assuming the information is confirmed.