The M96 Expeditionary Rifle is not a Stoner design. It is Alex Robinson's "interpretation" of a Stoner 63A, intended to externally resemble Stoner's gun, but designed and executed by Robinson such that no parts are interchangeable aside from the synthetic Buttstock. The result is a sporting rifle with ###y looks that is known to break Bolts, Piston Springs and Firing Pins. Whether those common failure points are a function of poor design or flawed manufacturing on the part of Robinson Armament, the fact remains that the M96 Expeditionary Rifle is NOT a Stoner 63 and any direct comparisons are pointless. Even the M96's designer recognized the limitations of his work and opted to field his new XCR design rather than attempt to work the bugs out of the M96 or even maintain the production line for critical spare parts such as Bolts, Springs and Firing Pins.
Stoner's talent as a designer of Small Arms was immense and unmatched in the Western World. Some might argue that Mikhail Kalashnikov was Eugene Stoner's equal, however I would point out that the Russian's single successful design pales in direct comparison to Stoner's plethora of ground-breaking designs with the AR-7 Survival Rifle, the AR-10 (and AR15) Internal Piston design with the use of Aluminum Receivers and Synthetic Furniture construction, the Stoner 63/63A Weapon System, the Stoner "Assault" LMG, the AR-180 and so on and so forth.
The unique brilliance specific to the Stoner 63 design was the ability to take a common Receiver and using conversion parts, turn it from a magazine Rifle/Carbine into a "Bren" configuration mag-fed Automatic Rifle, or into a belt-fed Light to Medium Machinegun. The result was an incredibly versatile and adaptable Weapon System favored by both the US Navy SEALS and the USMC in Vietnam. Unfortunately, the flexibility of the system was also its Achilles Heel, in that it was a somewhat complicated and high-maintenance weapon that required a high degree of training to properly maintain and operate. That said, it remains to this day an excellent weapon system, unmatched by modern designs in terms of its multiple configurations for specific mission applications. Unfortunately, the unique multiple configurations were never fully explored with the M96, limiting manufacture to the basic Rifle and a small number of "Bren" conversion kits.