AIController and RTS units

I wanted to know what kind of controller should I use to make units in a RTS game. I have not worked with anything relating to the engine AI yet,

For camera and the player, I used a player controller inherited class controlling a pawn inherited class.

For the units of an RTS I think an AIController as the base class would be the best I am not sure so asking.

Yes you will have to inherit from AI controller for a single unit movement
if you want formations or squads you will need to make a custom controller
that will handle a path planing - and then AI controller should execute the planned path.