Fused Personalities

I watched SU a bit, and I am not sure if anyone's noticed it yet, but the mental characteristics of a fusion seem to change based on the circumstances of their fusion.

Look at Sardonyx and Sugilite's second fusions, plus Opal-they show little personality, and were fused when time was of the essence. We see that Sardonyx and Sugilite's first fusions were done with not only utility, but companionship in mind- as a result, they were much more personal, making small talk with Steven and even showing off! Alexandrite was fused for a silly purpose and seemed very awkward... though the situation they were in didn't help anything.

If this is the truth, it poses the question- what happened to Garnet to make her so closed-off pre-Jail Break? Were Ruby and Sapphire just going through the motions of a fusion, putting their emotions before their mission before their forced split, kind of like parents who don't like each other but stay together just for their kids? Did it take getting split up and refusing to realize how important they were for each other?

Time to stop. I'm starting to sound like Ronaldo.