I got clarification and it seems this is intentional. While the combat tail goes through drone-like attack patterns, it is not considered a drone to benefit from the "Attack Drone" perk. The drone accessory is what is adopting those benefits, if I'm understanding it correctly.
Okay, for now at least, I've disabled the line about benefiting from the Drone perks for the next release. If the function is still inconsistent with the description, I may need to take another look.