Firing again for value v's firing again to get him to fold any pair is two different things. The question is whether he calls with nothing at all or not. If you're ahead with A high then you already got some value on the flop. I dont like the idea of putting too much money into the pot with high card v's a guy who'll call with any piece of the board.
A true calling station (which this guy looks like) is a dream for our plan of winning the most and losing the least, as long as we treat them accordingly.
