There is a relevant debate about bringing case studies to a brainstorming session. Some people say it narrows the team's perspective and conditionate them way too much. Others think the oppositive; it inspires people and opens their heads.
We don't have a fixed position. We believe it could be positive and negative. It just depends on how you do it.
If you decide to ask your team to bring inspiring examples to share before you start ideating, try having this approach; not only look at them but analyse them and gain insights.
You can do that by asking these two simple questions for each case:
What is relevant in this example?
Is there any insight you can gain? What did catch your attention?
What are the similarities with our challenge?
Are you trying to solve a similar problem? How did they manage?
It's a way to get away from the obvious and avoid copying the case. If you dig deeper into why it worked or why it's a good example, you go beyond format, shape and design.
So next time you doubt between bringing examples to your brainstorming, think how to make your team look beyond the obvious and learn something from it.