Too cool in some cases - IMO, when Sherlock is acting crazy, he needs to be reacted to as his being crazed. Joan, on the other hand is obviously expecting childishness because that's what she gets out of her Holmes, moreso than BBC's or even the Ritchie Sherlock.

My complaint with Joan not being a soldier is that soldier Watson lost his life's work through no fault of his own, while Joan is being described more and more by her show and herself as having screwed up and lost her confidence in a wave of guilt. I don't find that to be a particularly feminist reason for the female Watson's raisin d'être, and would have found a wounded army medic to be a much stronger character.