A quick update...
I've left the Sampans, Junks and Fishing boats.. they tend to go into 'orbit' with a torp hit... you should see the one fishing boat, it's so funny... after a torp hit, it goes into 'rocket' mode eventually 'diving' faster than a sub - will post movie later..
Other than that, they all take a max of 5 or so APs or HEs to sink so I'm not going to make any changes here.
I'm now onto the small merchants...later