How to analyze a team's projects?

I’m doing an assessment on behalf of my office’s leadership, and I’d like to take a look at an entire team’s projects to examine things like: projects with specific collaborators, how frequently projects are updated, etc.

I don’t see any sort of analytics built into the team view apart from a calendar, so I was thinking my best bet is to create a private portfolio of all of my team’s projects and use dashboards, custom fields, etc. Unfortunately, I don’t see a way to quickly and completely capture all of my team’s projects in a portfolio (we have over 100).

So, my question is, is there some sort of analytic capability that I’m overlooking? Or, is there some way to quickly get my team’s projects into a portfolio?