Looking at Shawnee's non-conference opponents the last 10 years:
2023: Stebbins (D2), Madeira (D5)
2021 & 2022: Valley View (D4/D5), Eaton (D4)
2020:
2018 & 2019: Greenon (D5), Tippecanoe (D3)
2016 & 2017: Thurgood Marshall (D3), Tippecanoe (D3)
2014 & 2015: Butler (D2), Springfield (D1)
2012 & 2013: Catholic Central (D7) , Troy (D1/D2)
Looks like Shawnee has always tried to schedule solid bigger schools, or similar sized schools that are very good. I think Greeneview would be a real possibility and a great schedule addition for both teams.
Shawnee has always been one that I'd love WLS to schedule annually, over playing the local rivalries like Ben Logan and Graham. I know they've dabbled in scrimmages like WLS does with Urbana, but I'd like to see it turn into real Week 1/2 games.
Greeneview-Shawnee makes a ton of sense though. And it doesn't appear that they've ever played.