I would recommend looking at the Norwegian system, where each region elects multiple candidates proportionately to the local votes, and all parties above a certain percentage nationwide shares a pool proportionally as well. It’s not perfect, but it gives a sane amount of different parties without the inevitable deadlocks of 100-party systems.
The national pool limit can tune the approximate number of viable parties.
I would recommend looking at the Norwegian system, where each region elects multiple candidates proportionately to the local votes, and all parties above a certain percentage nationwide shares a pool proportionally as well. It’s not perfect, but it gives a sane amount of different parties without the inevitable deadlocks of 100-party systems. The national pool limit can tune the approximate number of viable parties.