The SRH and the RH share the same overall strength due to having the same size cylinder window and using the same cylinders (where calibers are shared). You can take a .44 SRH cylinder and put it directly into a .44 RH without any issue (assuming the timing checks out OK). You can do the same thing with a .454 cylinder form a SRH and put it into a .45colt RH and have a .454 Redhawk. It is also possible to have either a SRH or a RH chambered to shoot either the .500 Linebaugh or .500 JRH.
The lockup on both revolvers is identical, utilizing identically sized components for both the cylinder latch and front latch.
The reason the SRH exists at all is in the late 80s, Ruger had a problem with RH barrels snapping off where the barrel screws into the frame. Not knowing the cause of the failure, Ruger designed the SRH to replace the RH in the product line as well as incorporating some new designs from the GP-100 (new trigger group and spike grip frame) and beefed up the area around the barrel to frame interface by adding the ugly snout. This was to add extra strength and support to the barrel assembly to preclude the barrel cracking failure. The intent was that when the SRH was released, the RH would be discontinued.
It was found out, fairly close to the release of the SRH that the RH barrel failures were not due to a design problem but due to the wrong lubricant being used on the barrel threads when the barrel was installed into the frame. This caused stress corrosion cracking on the barrel and the ultimate barrel failure. After correcting the problem no further RH barrel failures were experienced and there was no need to discontinue the RH.