David said he wrote 2 followers and 2 romances (he said it like that). We already know we have at least one NPC romance so David first companion isn't necessarily a romance.
Are you saying that he might have written more than two characters? But then you'd have to consider that he is probably still writing Morrigan... as head writer with extra job duties, I wouldn't picture him taking lead on any one else.
We've had a pretty even split so far. 2/2.
(Solas, Dorian, Cullen, Scribbles, and Leliana are the ones with mystery writers)
And we still have the second character for Lukas and Patrick.
Supposedly, Cullen was already half-written by Shelly before she left... whether or not they went off her frame work is another thing.