Think of a chorale, the harmony of this one is just spread out with very large chords. Practice the melody by itself, or with LH playing unison, to clearly hear the melodic contour. Practice soprano and bass notes. If you want to hear the harmony without dealing with the large rolled chords, condense the chords to fit under the hand.
Give melodic line the priority, and let the rolled chords fall into place. Ask yourself, how would a singer express this melody?
Do they have specific note values that they have to fit into? And does the right hand come in on the final note of the broken chord?
These things are more a matter of artistic interpretation. There is no set rule.