From Wikipedia –
‘Disproportionate dwarfism is characterized by one or more body parts being unusually large or small compared to the rest of the body. In achondroplasia one’s trunk is usually of average size, one’s limbs being proportionately shorter, one’s head usually larger, and a prominent forehead. In at least one case achondroplasia resulted in a significantly smaller trunk and head. Facial features are often affected and individual body parts may have problems associated with them. Orthopedic problems can result from multiple conditions such as diastrophic dysplasia and pseudoachondroplasia.
Proportionate dwarfism is marked by body parts being proportional but smaller. Height is significantly below average and there may be long periods without any significant growth.’
That’s how dwarfism “works” medically. I’d leave it up to the individual Machinist as to how to interpret it.