Use one of the following depending on the transcluding article. This will show all related articles while hiding the less relevant ones.
{{
WIAA Northwest District 1|A|4A}}
for 4A Conferences{{
WIAA Northwest District 1|A|Mixed}}
for Northwest 1A/2A/3A and Cascade mixed-classification conferences{{
WIAA Northwest District 1|B|1A}}
for 1A/2B Conferences{{
WIAA Northwest District 1|B|1B}}
for 1B Conferencesetc.