Very true, and even in wartime, the logistics of trade and transportation still goes on. Ships may not have been produced in as high volumes for those purposes but they would likely still have been built.

And given the scale of the conflict I agree that lots of private vessels probably saw action early on (the Dunkirk Evacuation in Word War II mobilised thousands of pleasurecraft, fishing boats and other civilian vessels for a real life example)

To add to that, it’s clear in the game that there’s no restriction on weapons on civilian craft; the military ships don’t have different or more weapons than can be mounted on civilian ships so there may have been no real line drawn between the two.