What happens when a primary nav link is used as a sub-menu item of the same link?

Non-profit client I am training to maintain (not redesign) the site I created for him has baffled me with his desire to alleviate his member users' confusion of knowing to click on a stand-alone common primary nav menu link. To alleviate this confusion (as he understands it), he has duplicated the About Us page and placed the duplicate as a sub-menu link under his About Us page. I fussed. He simply changed the name of the sub-menu item to Learn More, but it is still the exact same page. He claims his members don't understand they are to click on stand-alone primary navigational menu links. I find this baffling and continue to strongly object his changes. If he insists on keeping his About Us page as a sub-menu item of his About Us primary navigational menu link, what are specific risks that can occur? Is this actually an acceptable UX design option? I can't imagine this wouldn't have serious repercussions for site integrity and SEO, not to mention simply looking silly. Appreciate your input!

I had hoped to add screen captures, but the sub-menu is hover activated, so I can't grab the image. I hate to reveal the client's site for his sake, so let's try this for starters:

About Us (primary nav menu link)

  • Learn More (the same exact page as the About Us page; only the link name has changed to Learn More in the sub-menu)
  • How to Become an Official (the main focus of the public side of the site -- I have SEO objections to this page being moved to the About Us sub-menu as well)
  • Contact Us

This is a massive site with multiple cross-links. I am concerned about the links getting scrambled. I am also concerned about Google taking issue with this "looped menu" construct. If you agree my concerns are valid, please provide your experience that I might pass this experience on to my client. If you think the client is fine with this navigational construct, please let me know if this is nothing more than a UX option. Either way, thanks for your feedback!