I have read The Good Soldier .....
and fortunately it is not too long since I found it, as I do for most modernist novels, a bit boring. I don't know about Ford's wife having an affair, but Rhys was Ford's lover, Perhaps that's why Ford helped her out in her writing. Hemingway didn't care much for Ford. If memory serves me correct, Hemingway has a short section on Ford in A Moveable Feast.
Hemingway wasn't mean about Fitzgerald's writing ....
He admired Fitzgerald's writing. He didn't like his drinking or his language puntuated by four-letter words. He couldn't understand how Fitzgerald could behave so abominably and write such a beautiful novel as Gatsby. One of life's paradoxes.
Hemingway drank, but he never became publically intoxicated ....
as Fitzgerald did. That is what Hemingway didn't like about Fitzgerald. Even Fitzgerald's lover, the English woman Sheilah Graham, recounts in her book about Fitzgerald, Beloved Infidel, how Fitzgerald's drinking wrought a pesonality change in him. This is portrayed also by Gregory Peck in the movie about Graham and Fitzgerald.