no, in those scenarios play the receivers. I think that the "gospel of back" can get taken too far. It is generally advisable to have strong backs in wherever you can. But, at some point you gotta take the msot points you can. In this case you have to play those guys. They are top 40 fantasy producers across all positions. And hilliard plays the falcons thsi week.
I will add that two flex spots is a bit much thoguh.