Here is a couple of scripts that can help automate the Fab file system.
FBX Organizer copies all the FBX files inside each folder and copies them into one folder.
Multi File Import is used with Houdini. It Takes all those FBX files, places them in a GEO node, creates a file node for each FBX, a transform node for each FBX, and then connects everything to an output node
If you are using Blender just drag all the FBXs into the viewport and you don’t need the Houdini script
Instructions for each script are in the readme files on Github