OK, my whole goal in life now is to convince you that Red is the Main Character!
First off though, I totally agree about the commonality of terms. That is why I never ever use Dramatica terms in meetings. I know it instantly turns everyone off. Instead, I talk around concepts by using terms familiar to everyone.
For example the idea of "stakes" as in "what is at stake for the Main Character?" For the longest time I couldn't figure out what they were referring to until it hit me that what they were really looking for was what Dramatica calls "Consequences." To me, the term "consequences" is infinitely more helpful when compared to "stakes" when it comes to writing a story. The consequences are what happens when the Protagonist fails to accomplish their goal - the consequences of failing. In "The Devil Wears Prada" the goal is for Andy (Anne Hathaway) is be Miranda's perfect assistant. The consequence of failing that goal is that she'll have to write for a less prestigious paper/magazine. She fails and endures the consequences.
"Stakes" really doesn't mean anything which is why discussions concerning them often lead to endless circular arguments in story meetings. But when they ask, "What are the stakes?", now I just talk about the Story Consequences...I just don't use that term.
OK, so back to Red...what about this angle...
What personal problems or issues are we privy too that no one else is? Issues he would take with him into another story. The judge calls him a cold and remorseless man, but do we get to experience what it is like to have that kind of attitude through Andy? I don't really know who Andy is. Red, on the other hand, I feel like I am Red.
And what about the idea that he disappears for much of the end of the film. If he was the Main Character yet we weren't exploring the story through him, we would feel detached and unaffected by the moments that play out on the screen. Doesn't Red fulfill that role better? Aren't we experiencing what it is like to go from a place of despair to a place of hope?