Ancestry does have a funky name convention.
Setup your Folders in the Settings of RM (if you haven’t done so).
Up to you if you want the media in one folder or multiple folders ie: Census, BMD, Surname, etc.
Since the media are in 1 folder now, I would rename them within RM to a standard you want.
After you rename them, if you want go with multi-folders, you can move them and run the Fix Media Links.