Qb start, week 4 watson mariota or siemian

all of them has great matchups, I like siemian at home against oaklands mediocre D
Mariota and watson both have good matchups going against each other but a lot of division games tend to be low scoring for the AFC south

Which one to go with??

I am in the same situation except going with palmer this week. No running game and going against a bad defense