Wow - talk about your herculean projects! That’s very impressive, on so many levels.
But it’s interesting to hear how you tackled the writing together. I was picturing two people sitting at a keyboard, but this makes much more sense. That’s why the characters’ dialogue, etc, does have internal consistency; the episode or scene was written by just one person. Also, I can see how one person taking the “lead” is necessary for the whole piece to come together as a whole.
I suppose co-writing might bring other benefits as well. More room for personal preferences in tackling certain types of content. Or maybe free to enjoy writing one character more than another.