Reviewed examples
Realism changes with the subject. The hierarchy does not.
These examples span human portrait structure, animal faces, coat pattern, large facial planes, and hard anatomy. Compare what each stencil keeps before you compare how many lines it contains.
Human face
Keep first: Eye line, nose base, mouth width, jaw path, plus the shadow boundaries that locate planes you will need to rebuild.
Drop first: Pore texture, soft cheek gradients drawn as closed bands, and stray hair marks that compete with gaze for line weight.
Animal face
Keep first: Ear set, eye spacing, muzzle width, nose shape, and cheek or jowl planes, plus one or two coat-direction cues that explain form.
Drop first: Hair-by-hair inventory, whisker-for-whisker tracing, and background fur that consumes density without aiding recognition.
Patterned coat
Keep first: Pattern breaks registered to anatomy, with eyes and muzzle dominant so tabby stripes, masks, or blazes support head planes.
Drop first: Low-priority mottling, mirrored framing drawn at face weight, and fine eye detail that cannot stay separate at small widths.
Anatomy and hard structure
Keep first: Cavity openings, neck divisions, joint boundaries, and contact shadows that anchor depth before surface treatment.
Drop first: Small tooth divisions, minor interior skull marks, and smooth bone transitions hardened into false contour bands.
Read each example through that lens. The portrait pair tests occluded structure, the three animal examples test short coat, patterned coat, and large planes, and the skull tests hard anatomy. In every case, the stencil earns its place by protecting anchors you cannot rebuild later, not by matching the reference tone for tone.