Fine - tell 'em if they want to play that way that there are still four fources - weight, thrust, "total reaction" from the wing and drag from the airframe.
Or tell 'em that you have resolved the forces of thrust and weight into one force, call it the "speed independant" force, and the lift and drag into another, so that there are only "two real forces" acting on the airframe...
There was a discussion about this topic a while ago on the Instructors forum, but I can't find it now.