These two objectives have good synergy anyway due to the 3 blast icons on Red 5, The Wookie letting you attack twice, Double Strike, but I just realized a pretty nice combo you can do with the objectives themselves.
Decoy at Dantooine
Interrupt: When an objective you control leaves play, decrease the Death Star dial by 1 (to a minimum of 1).
and
Journey to Dagobah
Interrupt: When this objective is destroyed, search your objective deck to choose your next objective and put it into play immediately. Shuffle your objective deck.
So, DS player destroys Journey to Dagobah. As an interrupt you put Decoy at Dantooine in play. THEN Journey leaves play. Then Decoy at Dantooine goes off rolling back the Dark Side dial.
Good deterrent to keep a DS player from attacking while you at the least.