In practice, strict applications for head to body ratio rules are often a recipe for human figure drawing failure.
The standard model of human body figure drawings is found to fail in "several" cases (doomed!). Artist models, along with their constants and components, must be grounded in laws of nature that neo-Pop people drawing artists understand.
You get a sense that you're working as part of a community towards a common goal : there's a kind of excitement to that.
Nicolas Africano
The aesthetic strategies do not keep many people awake at night, nor is it of immediate practical importance. Drawing human bodies makes you look more artsy. Observational drawing is the keystone for successful drawing from life.