This is correct. The small one is just left over from when we replaced the models a few years ago. We didn't want to remove the old one from everyone's inventories.
It's a model, not brush. It can't be changed as easily. Maybe I'll get to it in the future if I do any more work to the training area and have time. Also if it was brush you'd want invisible, not nodraw. Otherwise it could cull entities behind it.