I don't think it matters one way or the other. Lou is the hitting coach and the head coach. The other guy they hire will have to be subservient to him. I wonder if Jaramillo factored that into his decision? I think the difference in the two is that Lou focuses more on approach - he emphasizes high OBP, patience, etc. Jaramillo, on the other hand, specializes in mechanics - developing and maintaining good mechanics in the hitter. They're two offensive minded coaches no doubt, but both specialize in a different area. While Perry and Joshua are both very good hitting coaches, the thinking was likely that they were just duplicating Lou's efforts - two doses of preaching OBP and patience, basically. With Jaramillo, there's an "expert," if you will, on fixing players' mechanics. Will that make a huge difference? I don't know, but it's intriguing nonetheless.