Presidente's SevenG 30

When I was done with every other achievement I only had four dynasty members. When I did was start the a new campaign starting with Cayo De Fortuna and finished the mission ASAP.

The second mission you want to start on the island of Bao Bao. After a while I was always able to get a new dynasty member, about 10 minutes into the mission.

It took me about an hour to get the remaining 3 dynasty members this way.