Hey, now we're learning, that's good.
My thoughts on the strap over the tunnel was to keep the tractor from going over the top rail at the front. It would also have to bend the frame for the wheel to get over the rail. Is it not a good idea to use the front rail for that? I strapped them both together to make one solid wide unit for stability. IIRC that is about the only time I hauled 2 side by side like that and I don't know why I didn't put one of them in the bed of the truck. Not sure on the straps being better, I have had 1 or 2 get cut as Ben had said. I see a lot of heavy equipment being hauled down the road and I would rather see chains and binders holding them down than a strap.