Tarkan/Konnink/Kipchak set vs line in AI

What’s the difference beween tarkan-line and tarkan-set in the AI files? My guess is that -line only encompasses castle tarkan and castle elite tarkan, while tarkan set also includes stable tarkans.
The same with kipchak, as kipchak-set would include Cuman Merc elite kipchak and konnik-set would include mounted and dismounted konniks. Is that correct?