The most important distinctive attribute of the viol or viola da gamba is, that they have frets, which is not the case for double bass, rebec and viola d'amore. They do NOT belong to the family of viols.
The baryton is a later exotic side development and IMHO should stand alone.
The violone is the biggest and deepest member of the viols, the smaller ones are missing (from small to big):
Pardessus de Viole
Please consider to introduce the german aliases according to this very comprehensive and profund article: https://de.wikipedia.org/wiki/Viola_da_gamba#Typen_der_Gambenfamilie