Arcee is an interesting character in the Bayverse movies, depending on what source you follow. According to the writers, Arcee's character was intended to work as a 'hive mind' and was one entity with three forms, blue, pink, and purple, and throughout the movie all three are addressed simply as Arcee.

Even though no other Transformer canon follows that, I always thought it was cool, so I stuck with it. *G* I should think Arcee could manage either singly or as a whole, depending on the situation.

Since she's really just one mind, she's not like the twins who are two characters with one spark. Both her consciousness and her spark are split three ways.

I call Jolt lucky. ;)