that is a good vid from VaEagle, that is the concept. That said I had the same concern as you; the Condor has four mounting holes in the "legs", I set up an 8 X 14 trailer with two Condors, offset. I welded nuts to stainless 4" X 4" plates and mounted the plates (underside) with smaller nuts and bolts in each corner. Overkill, but it I didn't need to worry about it in the mountains. Condors don't move around much with the bike loaded on them. Used D-ring slots on the sides and flip ups in the middle. I made the port side Condor permanent, I made the other one movable from dead center when pulling one bike, to starboard when pulling two. I mounted the port unit 18 inches forward of the other one so that the fairings would stagger. Try to balance the bike (you will need help) so that it isn't too tongue heavy, if you can, tape up the axle(s) location inside and position the bike like you would on a garage jack. You need some tongue weight so the rig isn't "popping", so place it a little forward of dead nuts balanced.
When you look in the side view mirrors and see your handlebars sticking through the side of your trailer, you will need to rework things. Hope this never happens, at times, "overkill" is a good thing.
OWL