Someone posted one of the charts of the advanced metrics, and it was surprising where Royce was. He gets way more grief than he deserves. He was actually significantly higher than Simmons on the x-axis and barely behind on the y-axis.
Nobody in the league really does what Rudy does. Part of that is the sets that Quin has designed, but mostly because he simply has a very unique skill set and has continued to hone his craft.
There are a lot of three indeed guys who are very solid on ball defenders out there. Simmons credits himself beyond what both the numbers, and comparisons across the league show.