Cast chemistry is also important. With GoT two hooked up, it did not end well, and actually affected the writing in season seven. Most casts are pros, show up on time, do their work, go home. Some gel well, and socialize and such with each other.Sometimes it’s subtle, sometimes not so subtle at all. A project can get done with lots of chaos and bad feelings (The Shadow) but it “reads” to the audience, no matter the skill of the actors.
I’m a big fan of bringing along new talent, or letting folks try new things. But I think it’s important for producers and showrunners to be sensitive to, and able to skillfully intervene in, interpersonal issues that might arise.
I have no clue to how Mark might be as a boss in this manner, but I bet he’s pretty good. Most important are empathy and smarts, and he’s got both. Some experience in running a company, too, I hear. I haven’t seen him get righteously angry in a while. I miss that!