That seems like some good takeaways. However, I’d expect that other groups (with more resources) can come up with more impactful projects than those you’ll find in the project ideas.
As for your three-dimensional tool:
How do you determine who the leader of a given activity should be? Also, I think it could be useful to include worst-case scenario/failure-mode thinking.
You can decide it by asking who wants to be the leader of a particular activity (the way that your group did) as well as inquire what resources and capital people have available to successfully lead that activity. Sometimes people have the motivation to lead activities, but they don’t actually have the necessary resources to do it successfully yet.
Agreed on the failure-mode thinking. I guess if you only take the best-case scenario into consideration, then you forget to assess the risks involved. On the other hand, I’m not sure it should be included in this initial brainstorming session or later when a possible activity is selected as a top candidate.
One shouldn’t include failure-mode thinking in the brainstorming part. However, while defining the project (prior to voting) it can be useful to talk about the failure-modes. E.g. prior to voting on our project on how to offset one’s climate impact we specified that we should be careful about letting it develop into a project which also focused on how people can offset the animal suffering they induce.