I no longer own a Hennessy, and don't really remember the orientation of the melted through holes, but I'm pretty sure they are side to side. That particular wrapping technique of the sling to the hammock is one that Knotty demonstrated, and I think it is as secure as any. I would say pick a method you like and go with it. I do think that having several wraps there adds security. As far as I know, most people do not use prussics on the slings to attach a tarp in the standard Hennessy fashion. I immediately switched my tarp to independent lines and suspended it separately from the hammock. I hope that helps.