Umm- heds pastede on, really. Forget Conan Doyle's version entirely. Werewolf Holmes with short hair is the idiot genki one who so far has had one stab at deduction (first story first page) and gotten it woefully wrong. (Though one cherishes his 'I see you have been enjoying the tomato juice they serve in Whichever Square.' Tomato juice, uh-huh.) Vampire Watson with the long hair solves all the cases and has dialogues with the sad spirits of the murderous entities encountered so far. The zombie is the supposed Jack the Ripper who keeps saying he isn't. Mrs. Watson is the ghost of their landlord's daughter.
And there's another thing I'd forgotten in the course of a decade- in this series at least JET *cannot* tell a coherent story. Things pop up out of nowhere, no-one says what they are, no-one explains who did the murders, we are to assume some kind of possession I suppose but that's rarely stated either. In that Mrs Hudson story we have her father, an old man, and we have herself, a young female ghost, and suddenly we have an aged female and a cryptic note to the effect of 'gets like this when in a state of shock', plus a bunch of zombies climbing in the window yelling Gramma! You OK, Gramma!? Who is this old woman? Three times through and I still can't figure it out. Readerly confusion may have several causes. There's Ima Ichiko subtleness and misleading red herrings, and then there's this, which looks like sheer incompetence.
It's an early series, that I do know. Maybe they got better over time.