The bog problem is that they are junks, and fishing boats (I'm not sure any are actually sampans).
What the game lacks are a few very small japanese ships that were very much legitimate targets. Barges, luggers, the sea trucks, etc.
All the above are <1000 tons.
The threat of air attack in the SWPA resulted in the shipping tot he front becoming distributed instead of concentrated in larger carriers. So convoys of barges, luggers, sea trucks, etc sailing at night, camoflaged on the coast during the day.
The current "sampans" have to fill the role of native craft as well as japanese shipping.
tater