If the three ships work together, yes, that would be optimal.
Are you sure?
I only ask because the different-ship-for-each-link plan involves a lot of unloading, storing and reloading of cargo between ships ... and modern economics tends to favor a handle-it-only-once approach. What are the labor, storage and time-delay-between-ship costs?
I am not arguing that it would not be optimal (since the rules do not address these issues), just that it is not as obvious to me as it seems to be to you.