This was tried in CS as a showmatch at Katowice 2016. Different game obviously but there's plenty of similar principles.
Astralis (ranked #4 at the time, ended up losing in semis at the main event) played vs 2 different teams of random matchmaking players (ranked between GN4 and SMFC), where Astralis tried winning rounds (CT side only) with as few team members as possible, starting with only Device.
It was restricted to one side of the map (Dust2 A site), which favors the CT in terms of manpower, but also allows Ts to commit to a full 5 man execute without worrying about retakers or lurkers. The closest equivalent in the TF2 version would probably be to prohibit backcapping, to force a legitimate teamfight.
Device alone got overwhelmed after only 1 kill
Device + Cajunb went 5-0 while trying to zeus people
Karrigan alone won his first 2 rounds but ended 2-5
Karrigan + Cajunb went 5-2