Then why are there Gorn and Nausican ships "wandering" thru Federation sector space and harassing Federation colonies and merchant ships?
Accoring to your reasoning shouldn't those be "Klingon Defence Force" ships?
You are correct, they are not part of the Klingon Defence Force, but Nauusicans are well known to be pirates and criminals just like the Orions.
The Gorn have more of a personal interest in certain regions of federation space which is revealed in several of the episodes.
But ultimatley the Klingon Empire would most likely allow the Orions, Gorn, Nauusicans to harass the Federation while the Klingons go on the offensive.
It is a very old concept and practice, we had them on earth centuries ago and they were known as....Privateers.
Pirates/Freelancers given permission by a goverment to sieze and plunder ships belonging to a certain nation.