[3] Regulars - Two Shiplord Regular craft, their profiles beyond ancient, orbit the life bearing worlds of this system. Why are they here?
[4] The Untamed - The closer world to the system's odd sun, this one appears to lack any Shiplord presence beyond the Regular Fleet dreadnought in high orbit. What secrets might those dead cities hold?
[2] The Inhabited - The second planet, this one is home to a true Shiplord enclave. You've visited one safely thus far, why not another?
[1] A Troubled Sun - Something is amiss with this system's star. You cannot tell what. Perhaps you should find out.
Above reasoning for A Troubled Sun: it lets the team build up a more complete picture of Shiplord patterns in-system before going anywhere else.
Otherwise, while the Untamed planet is the safer option, any answers it may hold likely require context to interpret. We shouldn't necessarily assume that the Shiplord enclave is a tourist site like the Zlathbu homeworld, but it's likely to have substantial amounts of information. My guess is that the two dreadnoughts are museum ships, but approaching those is going to be difficult... and there may be guided tours of the ships starting from the inhabited world. Why sneak up on them if there's a chance of getting said guided tour?
EDIT: Also, with the uninhabited world... last time I checked, planets are big, and we don't necessarily know where to start searching. The enclave hopefully provides context as to where to start searching. Also, slight change on the ranking (switched the Regulars and The Untamed)