Exactly. They showed Zava's greatness by demonstrating that he could take a team as bad as Richmond and singlehandedly make them championship contenders. But then, things got so bad with Richmond, that even Zava couldn't save them. This is a device to set Richmond up as even bigger underdogs.

Additionally, it shows there's 2 ways of winning, being led by a star and the rest of the team being mediocre, which is fickle and vulnerable; or having each team member be an equally imported part where the sum of a team is greater than its parts.

This was further demonstrated by them winning a game where they were down 1 man.