For the future, here's an idea: ...
The number of places that qualify directly should be determined based on the number of participants, and these will be:
a) only those who won all their games
b) or also those who won all games except for one loss
This approach will also make pre-arranged draws in the final rounds pointless.
As an alternative, you could avoid fixing the number of places that guarantee direct qualification and instead specify that to qualify, a player must score >= the maximum possible points minus 3 (i.e., a maximum of one loss), and the remaining players will play one round of playoffs at the end for all the remaining places – this will partially solve the problem of many players losing motivation early on and completely solve the problem of pre-arranged draws.