more_fonts/fonts/fc_local.conf

<?xml version="1.0"?>
<!DOCTYPE fontconfig SYSTEM "/etc/fonts/conf.d/fonts.dtd">
<fontconfig>

    <!-- Alias similar/metric-compatible families from various sources: -->

    <alias binding="same">
      <family>Arimo</family>
      <family>Arial Narrow</family>
      <default>
      <family>Arial Narrow</family>
      </default>
    </alias>

<!-- -->
    <alias binding="same">
      <family>Arial Narrow</family>
      <accept>
      <family>Arimo</family>
      </accept>
    </alias>
<!-- -->

</fontconfig>