Just to reiterate what has been mentioned in some of the other answers: the standard way that complications in an application (e.g. explaining TCS work/publication criteria/other issues to a hiring committee/department/dean) are dealt with is via a carefully crafted letter explaining the situation.
So: if you are submitting an application in which you get to nominate your letter writers (which is likely the case, since you describe yourself as a junior mathematician, which suggests that you will be applying for tenure track jobs, for which typically you choose your letter writers), then, when you choose your TCS letter writer, be sure to choose someone who understands how to communicate TCS issues to mathematicians. In fact, hopefully you can choose a letter writer with whom you are sufficiently comfortable that you can raise this issue with them. (Not the issue of breadth being a weakness --- I don't think it is appropriate to raise concerns about weaknesses of your case with a letter write; those are for them to judge and comment on if they choose too --- but rather the concern that a math hiring committee may be unfamiliar with the TCS culture; I think this is a legitimate issue to raise with a potential letter writer, and if your chosen letter writer does their job properly, they will then include some explanations of TCS publishing culture and so on in their letter.)
More generally, I would think that generally speaking breadth would be regarded as a strength in a candidate, but not at the expense of quality and depth. But this is not something you can really control, since surely you are already trying to do the best work you can!