This just in from Beck & Woods re Lee / Regan / who is Protagonist question:
“We’ve always viewed Regan and Lee as shared protagonists. Each has an issue communicating with the other, and therefore their entire arc is to resolve that conflict. While we’re aware of our “protagonists” during the writing phase, our goal is to always flesh out every character equally (even supporting and tertiary characters), so that they feel completely real, rational, and dimensional.”
There you go from the originators and co-writers of the script.