This answer didn’t really answer the OP question at all and was actually really quite vague.
@ZChurney3 from my exploring currently as we have a massive DAM project underway, aside from a completely manual process, Hubspot has no current tools in place to help manage the files other than the obvious folders and a naming system put in place by your org. Support and our account manager have both suggested exporting the files and using an external third party to help clean up, utilizing it as a reference for locating dupes etc. and then searching the files network and manually organzing within HubSpot. Following that implementing a plan to manage files moving forward.
Hope they beef up this area for others, by then we will already have moved into our DAM solution and will have to put in the time ourselves to clean up. If I could only go back in time! haha