Ideas ferment over time. I think writing in a group simply expedites that process. I have had a feature film script that I haven’t written a single page for, but have been mulling over for years now. If I don’t collaborate with other writers, the ideas simply have to ferment like a wine in my own head. I tried the process of doing the 3×5 cards for this a few years ago, but I never finished. That workflow might be how I crack the nut this time.
And I still might work with other writers on it to make it perfect. I don’t have a lot of ego as a writer. I know as a producer what I want, but getting it sometimes requires sharper minds than my own.
Sometimes with a complex script, the writing is the easiest part. The preparations take the most out of it. Having a solid idea of scenes, the overall plot, the characters, and events all coalesce into a screenplay easily – once those elements come together well.
This is more the role of creative producer, and this process is called development. Even on the microbudget level, the technical terms have meaning and hierarchy needs to be defined.