The only thing is that all my freight cars are horn, hook couplers+1 on the BNSF unit being an Athearn GP38-2
Older "blue box" model, would have delivered with the old "horn-hook" couplers, but knuckle couplers are easy to swap in. Just need to be careful using metal couplers on the existing mounts on this, as the Athearn metal frame forms part of the electrical circuit, so if you coupled two of these together in the wrong orientation, it could short-circuit by creating an electrical path with all that metal.
So convert them, too. Anything you buy these days (except "new, old stock") is going to come with a knuckle coupler out of the box.The only thing is that all my freight cars are horn, hook couplers