that same reasoning already applied to snecma, namely successful engine developer, needs cash , can provide manufacturing knowhow and some TOT - still it didnt work , and it should be worse with usa companies who are under stronger constraints not to transfer tech ......i dont think your idea offers any paradigm improvement over the stuck situation with snecma
genine joint investigation arrangement with another strong RnD nation like japan or korea who are seriously seeking to develop their own is the best way out ....plus buy engines from whomever to keep us going meantime