Question

I don't have any experience on committees making these kinds of decisions, so you should take my answer with a large grain of salt (or perhaps just ignore it). I would expect that the dominant factor in decisions is going to be how good your research is in your strongest specialty, but that to the extent that breadth is a factor it's a plus and not a minus. Much like with teaching, people have a tendency to make the leap from "X is good, but isn't important enough to make up for deficiency in Y" to "X is a minus and not a plus."