I noticed we can't get redcoats and naval officers like the scurvy dogs. Really would look forward to this even if it was a crown shop item unlocked by a quest. I love Marleybone companions.
Swashbucklers get a Dog Officer and Musketeers get a Dog grenadier. If your parents got shipwrecked than I beleive you get a scurvy dog like companion named Lucky Jack Russell. Privateers get a Kurgha Captain. So there are a few Marleybonians you can get.