The current clash format does not really drive competition between clubs. It is currently only a contest to turn out the most played rounds per club.
If I may suggest an alternative, why not have a limited number of players allowed to play a particular round. And match clubs not by level, but by number of members in the club.
As an example, clash is open to a percentage of players from each club. once all involved play one round (within an x hour time limit), the clash is scored and the winning club moves on.
You all could even make it a bracket type format and set up consecutive rounds against the higher scoring clubs.
The key to making this competitive though is to limit the NUMBER of players from each club and making it one round per player.
Wouldn't hurt to make the prizes a little more rewarding. Maybe a sleeve of balls to teams in the top 10. It is really all ones and zeros from the programming side anyway right?