OK so "Three's Company" was a remake of "Man About The House," and on that show, the characters that corrsepond to Helen and Stanley Roper were named "George and Mildred."
And the oft repeated joke was that the name was abbreviated, G. Roper (Groper -> Get it). So when they Americanized the show they changed it to Helen and Stanley, which is stupid. Why not just use the first name since they used the actual last name?
And even more stupid was in "Man About The House," the character named Chrissy corresponds to the "Three's Company" Janet.
The character of Chrissy in "Three's Company" corresponds to Jo, in "Man About The House."
Larry was the best friend in both "Three's Company" and "Man About The House."
I can see why they changed the lead male of Robin in "Man About The House," to Jack in "Three's Company," because Robin is thought of more a girl's name in America.