Unity is but one element of a painting. Even that Basquiat employs a form of unity. There is a commonality to his brushwork across the entire painting. He has bounced the blue of the background into the skull and the black of the skull into the background. I use a reddish underpainting that shows through across the entire surface lending a color unity.
But unity isn’t the only element of art/principle of design or composition. Contrast can be equally important. Movement. Repetition. Pattern.
The narrative is a secondary element to a work of art. HOW is more important than WHAT. A great many masterful paintings are not narrative at all. Is it even necessary to understand the narrative in paintings such as these:
Knowing the narratives may lend an added level of appreciation but it is no more central to art than it is to a work of music (a song or opera).
Manet painted some absolutely exquisite paintings that are but tiny simple still life... a few flowers, a bunch of asparagus, etc...
I’m not surprised that a curator of contemporary art might suggest she doesn’t think much about composition. A number of critics have spoken of our era as the era of post-aesthetic art. The concept is everything. This is the result, in a good part, to art schools and university art departments stressing theory and concept over aesthetics and studio experience. It’s much easier and cheaper to teach someone to simply think the right idea... preferably something concerning gender roles or race... than it is to provide studio space and spend endless hours learning how to realize a visually engaging work of art.
It is funny that your curator would cite Bosch as her favorite painter. Yes, his works are laden with mysterious narratives... but they are also immaculately well composed. The strength of his structures hold a teeming details together.