Right. I’m agreeing they (sort of) fit) - with the “six-pack” type of holder for thepointed end.
But the wasted space (between and around the amphora inside the hull) is more than 5x the volume inside the bottles!
They probably stuffed the intermediate areas with other cargo whenever possible, and straw or other stuff to keep them from knocking together in rough seas.............
[ But the wasted space (between and around the amphora inside the hull) is more than 5x the volume inside the bottles! ]
You could always pack in grain around them racks.