Do you think Vivian and Bill would have gotten along eventually if Bill didn't overhear her complaining about him playing her husband? They do seem to have had friendly moments here and there - in a video from her winning an Emmy, he is pattung her on the back in s congratulatory manner, and they did appear amicable in the clip.

That is hard to say.

You would think they could both have realized how lucky they were to get those cushy gigs and had each others backs.

I wonder if Lucy and Desi ever told them to try and find a way to work out their differences for the sake of the show. But they were too busy squabbling themselves.

Ah, showbiz! :)

They hated each other so much.

Actually, I believe the Arnazes and the writers were very aware of the Frawley/Vance mutual disdain. However; they early on decided that it would be more believable for this duo to play a supposedly older, jaded and war-weary couple if they genuinely had antagonism for each other than had they gotten along swimmingly. Also, each of them seemed to get along at least civilly with the Arnazes so it helped that each of the Ricardos would buddy-up and conspire with the Mertzes of their respective gender if the Mertzes themselves weren't getting along. It was a good contrast to the 'lovey dovey' Ricardo demeanor and, especially, Lucy's (the character) own starry eyed idealism.

Alas, despite each of them liking Mr. Frawley and Miss Vance regardless of how they themselves viewed their marriage, the Arnazes would get somewhat frustrated with the other couple's growing disdain to the point of Miss Vance flatly refusing to work with Mr. Frawley once her Ethel obligations were done. I think the fact that Miss Vance's refusal totally sabotaged a possible Mertz spin off somewhat cemented Mr. Frawley's disdain for her (who had been willing to endure his dislike for her to have this intended series provide him and his even older brothers some security in their twilight years).

Although they expressly put it in Mr. Frawley's contract that Fred would be permanently written out if he showed up too soused (and Mr. Frawley managed to keep the cork plugged until each show was wrapped),I seriously doubt ILL could have lasted or been as fondly remembered without Fred's vital sour notes giving the right balance (and, as much as Miss Vance might have preferred playing the Widow Mertz, I seriously doubt that would have worked long).

Ultimately, the Arnazes both knew what worked for their show and knew that they couldn't do without either Mertz so I think they likely decided their costars' feuding was a necessary evil they had to endure for the greater good!