Haha I love the dramatic contrast between a Kanitalian view and a Rosilian view of the same situation. (cause drama to avoid looking conspicuous VS. don't cause drama you'll make us look conspicuous!) 

Anyway. My thoughts as far as the progression of events are:

We go to the Castle to look for clues/blueprints. We encounter our two new additions there. After we end up all deciding to go together (for one reason or another) We find a clue that points us toward the "shipyard" located on the "back" of the island. Then we can have a nice dramatic moment of seeing the half-built airship, and find what we need/escape from there. 

Once all that's wrapped up, I think I'll go ahead and do the time skip ahead to the completion of Rose's first airship. This would be your cue Iarumas to figure out some excuse for having a bunch of rapscallions on board.