No, I personally wouldn't.
Blount is in a very crowded backfield and who knows how that is going to shake out. He could rush for 2 TDs and 10 yards... or he could not play at all... no one knows what is happening in Detroit backfield.
So I would go with the players that you know are going to play. and If you are going to be in a close matchup, hopefully 1 of the Rams' WR will get you a TD... but I wouldn't expect a TD from both of them.