A long shot here, but could Ships of the French Arm cover only the ships of the French Arm? Maybe the Manchurians were simply building their colonial empire in the Chinese Arm according to a long-term plan, building up Delta Pavonis and laying the skeleton of an empire elsewhere while building up a sufficiently large passenger fleet?
That still might leave the further French Arm, beyond Niebelungen or Beowulf, hard to explain. Many of those worlds were only recently colonized but have still accumulated populations in the millions, if not in the tens of millions.
That is definitely what the SotFA covers - but even so, there's not a really large ship in it for moving *colonists* on the French Arm.
The New Orleans Liners are great, but the routes listed in the description seem to be confined to the older colonies.
The Vaca has the next most, but it's slow and a converted cattle car. If you wanted to get picky you could point out that it's Brazillian, and Brazil sends it to the far end of charted space from the French Arm - but it was still good to include anyway, since they never did a 'Ships of the Chinese Arm' or 'Ships of the American Arm'.
But like I said a few posts back, "You'd either have to posit more ships than seems to be provided for, or there are a few great big ships 'off camera' somewhere."
It would have been perfect if they could have put the British "York" Colonizer in the SotFA book, since it
a) carried a lot of people as a Colony Ship, not a liner
b) belongs to a nation that has colonies in the French Arm and might more reasonably be seen there than the Vaca, and
c) is mentioned in more than one colony write-up in the Colonial Atlas but was removed from editions after the first one, Traveller 2300.
A few years back, on one of the other 2300 discussion boards, I asked what the stats of the York were, and a couple people were kind enough to post the info. I've got it on my website - I don't know how to put it in as a link, but here's the address. It's down under "York". [Yes, a shameless plug, but it does relate to the discussion.]
http://www.geocities.com/canada2300vj/
Ah, it's a link automatically. Double plus good, citizen!