Good Morning, Wanting to confirm rather than speculate. In the Sectorial charts Teutons link options include Duo, Haris and Core. In the Army builder both types. Teutons do not have the Duo skill. I assume that this is to allow them to link into a duo with say Knight of Santiago or Knight of Justice as these profiles bring the duo skill.
In the charts, it lists Haris, core and "special", which is specified on the next page. That special is a duo.
Please be aware that fire team rules are due for an overhaul, so don't get too invested into how things are working currently.
