Hi,
You probably have enough NICs, just don't terminate them all in one switch. If you have sufficient ports to do what they did in the article, have them cross connected, and you have no single point of failure, that's the goal. I would give Storage an additional adapter however such that even if its primary path fails, the failback path is dedicated to storage and not shared. Just requires a bit of tweaking of the diagram to achieve.
Good Luck!
Mike