Unfortunately, I don't think your scenario would have played out the way you'd like it to.
What cars were kicking ass and taking names in the late 80s?
Taurus
Accord
Camry
Maxima
IMHO, what you just described would have looked like this.
1987, GM debuts the new G-bodies. Ford debuts the new Taurus, Chrysler buys AMC/Introduces a K-car.
1988, auto rags rave about the new taurus, mention Camry as a worthy competitor, wonder allowed why GM hasn't jumped on the bandwagon with FWD for family cars.
1989, G-body sales reach their lowest point in 5 years. Ford recarpets every home in Dearborn with carpet made with gold spun from hay. Chrysler introduces another K-car.
1990, GM sales continue to slide, N-bodies are the only bright spot. Ford issues press release. "Neener neener neener". Toyota issues press release "We're coming to get you Ford", Chrysler introduces another K-car.
1991, GM updates the E-bodies, G-bodies finish in last place in all auto rags for the 4th straight year. Auto rags wonder allowed who is steering the GM ship stating "Even Chrysler gets it.", Chrysler introduces another K-car. Toyota's assimilation of the U.S. begins with redesigned Camry. Honda issues press release, "Me too!"
1992, First Iraq war, oil skyrockets. Last year for the E-bodies, G-bodies get a mild MCE. Taurus gets mild MCE and pisses all over G-bodies. Ford wisely discontinues 4-cylinder Taurus. Camry 4-cylinder sales climb. Chrysler introduces a K-car.
1993, GM is now borderline bankrupt. Gets government guaranteed loan, Introduces W-body. Taurus sales plateau. Toyota installs mind control device in every american, free of charge. Chrysler introduces the LH cars/apologizes for K-car.
1994, GM introduces H-bodies. LeSabre/Eighty Eight/Bonneville sales take off. Buyers confused by the similar sized G-body and W-body choose the W-body because Car and Driver told them to. Taurus sales fall, ford blames Toyota's mind control device. Chrysler introduces a LH car.
1995, G-body discontinued after W-body outsells it 5-1. Eighty Eight named best value large family car. Last good year for Ford. Chrysler introduces an LH car.
1996 B-bodies dicontinued, H-bodies set sales records, Tahoe now best selling Chevy after the Cavalier. Ford redesigns Taurus to look like a fish. Parking lots slowly becoming a sea beige Camries and Accords. Chrysler introduces an LH car.
1997, W-body MCE. Motor trend issues proclamation "Pushrods are teh suxors!", w-body sales plummet. Ford rips the carpeting out of every home in Dearborn. Toyota issues press release "All your base are belong to us". Honda issues press release, "Me too!". Chrysler introduces cloud car.
1998, W-body continues to fail to meet sales goals, Chevy selling every Tahoe and Blazer they can make. Ford lops off it's own head. Chrysler ... oh heck, you know the rest.
1999, Olds dies. GM files for bankruptcy protection. Analyst speculate it was because of GM's late entry into the family sized FWD market. Kirk Kerkorkian takes over Chrysler, introduces MCE LH cars. Ford becomes irrelevant.
2000, Mercedes Benz buys General Motors, proclaims "Merger of equals". Buick, Pontiac and Cadillac immediately canceled.
The End.