My vote for seniority is straightforward - F.O.S.
https://www.youtube.com/watch?v=R60z_7vZ0YI
You heard me correctly- Feats of Strength! If that does not work out we could possibly combine an elimination tournament of Rock, Paper, Scissors with a airing of grievances judged debate. I'm just spit-ballin' here so feel to contribute some possible ideas.
Scoop