Small closets need tighter decisions, not simply smaller components
In a reach-in or compact walk-in, every opening competes for the same few inches. Start with the closet door and the clear opening it creates. A drawer bank placed behind a bypass panel may look fine in an elevation but still be awkward to use.
For many small closets, the highest-value move is separating short hanging from long hanging. Shirts, folded pants and jackets usually do not need the full floor-to-rod height. Double hanging can use that vertical space twice, while one dedicated section handles dresses, coats or other long garments.