Function has_balanced_components 

fn has_balanced_components(
    units: &[Unit],
    files: &[FileHandle],
    extents: &[Extent],
    tolerance: u64,
) -> bool

Whether every group of conflicting files among units is balanced, see has_balanced_runs. Runs of separate groups never overlap, so pairing a dominant run with the peer of another group would hide it. Takes O(K²) conflict checks for K files.