They both strike me as very all-or-nothing hitters. I would like to see Kearns batting lower in the order, and Church batting higher with some OBP guys on either side of him.
I like your thinking, but unfortunately, we are lacking some options. Church is actually keeping a high OBP, and Manny said he would be in the 2 hole if Nick was healthy. (I actually would prefer Nick in the 2 hole, but I would take Church if he wasn't one of our best power options. Against lefties, Church's spot in the lineup is a lot trickier.)