I of course also use a Hitch Lock bit when the trailer can be easily moved by one or two people anyway,locking the hitch is not a lot of protection.
These can easily be dragged by the safety chains through a hitch for some thieving distance.
I got the "Clubs" to provide some actual deterrence and I feel they do.
They clamp around the wheel/tire and the spike thing prevents the wheel from turning more than about 3 inches.
Now these can be cut off fairly easily I suppose and I even have a cordless Sawzall that would probably make short work of them(like it does everything else) but it is going to make a scene to cut them.
I have been in the security business for a long time too and there is never just a single solution to securing movable objects.
Parking in good motion detecting light
where there are people who will notice and securing the rig to solid object or trying to make the rig immobile are the best if it can not be locked inside somewhere.
Of course if they really want it,they will get it.