Leads can hop from stream to stream but it can get tricky depending on what you're trying to achieve. It's also possible to use email programs nested within engagement programs to alter someone's path within a single stream but that can get tricky as well!
We ended up stacking all of these in a single stream in a Fundraising/Product Interest order that makes sense. We're really only measuring success on if they accessed a piece of content. We also just added a "Fast" stream if they're engaging with a lot of our content, in order to crank them through the program faster. We simplified it quite a bit, but with a combination of Smart Lists and Email Performance reports, we're off to a great start!
Thanks for checking in, and have a good one!