I think those are the strongest relationships, because they don't need to say anything, they just feel it. Their feelings come across in their actions, like how determined Kanan was to rescue Hera and how he retrieved her family artifact because he knew how much it meant to her. Besides, the war against the Empire didn't leave much time for romance and when Hera did finally say it to Kanan, he sacrificed himself not long after (I actually predicted something bad would happen once Hera made her love confession).