Applying for postdoc positions without first author papers?
I doubt that very many employers treat hiring post-docs as an accounting problem, counting up the chits. Instead, I would ask, how do your skills meet our needs? Some places with great reputations and heavy competition for positions want a way to encourage only the top candidates to apply, but even there, they have needs for skills that you may have, or not. 

As in any application, stress your positives, your skills, and interests. If you get rejected then keep looking. The competition may be at a high level, but the evaluation is much more varied than just counting publications.