@real_tabasco_saucecorrect me if i'm wrong but
You can try specify same way is done on that template and it should override parent's requirements:
<Identity>
<Civ>germ</Civ>
<GenericName>Cimbrian Clubman</GenericName>
<SpecificName>Kulbawigô</SpecificName>
<VisibleClasses datatype="tokens">Champion</VisibleClasses>
<Requirements>
<Techs datatype="tokens">phase_village</Techs>
</Requirements>
<Icon>units/germ/infantry_clubman.png</Icon>
</Identity>