Why are we presented with a RHH having "percentageControl" = 100% without any shareholders being present?

"Control" is not only a matter of how many shares one owns. For instance, in sole proprietorships there are no shares, and thus no one owning shares in the company.

That is the reason there may be no shareholders but still a RHH that controls the company.

Remember that RHH is defined as a physical person that ultimately owns or controls the customer.