I vote no. different designs.
Pick them up side by side sometime, you'll change your vote. They are two different designs, which share the exact same cylinder frame and cylinder, minus the nose-job on the front of the SRH and the grip tenon/frame. The exterior profile for the purpose of holster making is exactly the same, so RH's and SRH's of equal barrel length fit the same holsters.
Other than the sidewall contact with the barrel thread extension, the "critical fit" areas are all the same on both SRH and RH's. If you trace both, the lower front corner of the frame, the top strap, the hammer and back line of the frame, the trigger guard, and all of the diameters and thicknesses are identical. For equal barrel lengths, all of the holsters are interchangeable.
The SRH was released as a response to reported barrel failures in the RH, so the "pinch hit" was to extend the nose of the RH and offer more support to the threaded tenon. The opportunity was taken to upgrade to the popular GP100 2 spring action at the same time. The Redhawk was released in '79, then in the early 1980's, a few barrels broke free due to an internal error, and the redesign was faster than finding the solution. The GP100 had been released in 1985, and the SRH redesign came to market so quickly after the barrel failures were reported - and with virtually no investigation, it's rumored the SRH was actually planned for release as a "Gen 2" Redhawk, upgrading to the two spring action of the highly successful GP100, however, the "need" of an extended nose gave Ruger a unique marketing opportunity to launch a 2nd gen as a completely different model, calling it "Super," and still sustaining access to the market which favors the traditional grip and barrel styling, and making use of the casts & tooling for the RH which were only a few years old at that point.
Not too many barrel lengths overlap, only the 7.5" in standard models, but there are a handful of Exclusive editions which overlap for holster fit, such as the 5.5" RH holsters fitting the SRH Toklat, or open toe 2.5" Alaskan holsters fitting the 2.75" RH Kodiak Backpacker.