From that paper, table 4, large files had an average # of fragments around 100, but a median of 4 fragments. A handful of fragments for a 1 GB level file is probably a lot less seeking than reading 1 GB of data out of a 20 GB aggregated asset database.

But it also depends on how the assets are organized, you can probably group the level specific assets into a sequential section, and maybe shared assets could be somewhat grouped so related assets are sequential.