JennH said: "And if the Lin/Odom thing is true, that is tragic. Because there's a new conversation to be had about why he would have chosen him the first place/why those in charge would hire a principal cast that doesn't get along. Especially two that play against each other almost the entire show, Ala Kristin/Idina."
It's not tragic, it's the way the world works, including showbiz. They hired the most talented performers they could, whether or not they get along doesn't matter. And they are antagonists, so really, if it's true, them not getting along would only make their performances better.
I don't know if Lin and Leslie knew each other beforehand, but if they didn't, then there's no way of knowing while making casting decisions whether or not they get along.
Of course, people in showbiz want to work with their friends, but it isn't always possible.