It's differentiator in sense engine manufactures are part of western aviation industrial complex and can limit access, i.e. COMAC sanctions. Unless you're western core, you do not have guaranteed access. I think Embraer is creeping on to bottom end of narrowbody, but they're far from wide body. And with respect to topic, modern strategic tanking are wide body size, i.e. Embraer E190 is not same heavy league as KC46, MRTT, Y20, Il-78, and Embraer has not demonstrated ability to go beyond regional narrowbody. Fielded widebody options is really just Airbus/Boeing duopoly, AVIC/Xi'an, UAC stumbling along from legacy USSR stack.