IA roles : common approaches?

I am now coding (blueprinting actually) behavior trees for my AI. And I was wondering what’s the common approach to handling different roles / behaviors in AI.

I was thinking on setting IA Role Tags in AI to know which behavior to run. Another approach would be to spawn each AI already with a sub-behavior tree. Another way would be to set a variable within the AI with the current role and use that as a discriminator. Maybe other ways I haven’t thought of…

What is the common approach here? The Character blueprint is the same for all IAs for now, so we can’t discriminate using the class type.