With Rolls-Royce and Pratt talking about making engines for the 737RS, the proposals made by Pratt and RR are different. Pratt is talking of a geared turbofan, while Rolls-Royce wants to use a three-shaft design for the 737RS engines. If IAE stays together, it will indeed be a hard decision to choose the design of the engine.
This article says that Rolls-Royce and Pratt may eventually join forces as IAE, but different proposals can split IAE up. If the 737RS uses a narrowbody design, it could become the first Boeing narrowbody to be available with three engine options (CFM, RR, and P&W). Before the 757 was unveiled, all Boeing narrowbodies used only one engine option, Pratt & Whitney. The 757 was actually supposed to have three engine options, including GE, but with the lack of interest from airlines for the GE engine, Boeing cancelled the offering.
What are your thoughts on this? Could the 737RS market support three engine manufacturers?