What activities provide the best results in aligning values and behaviors across teams?

State what behaviour you expect and train your middle management to walk the talk.

I usually create a product manifesto (referring to the agile manifesto) and then force my leadership team to use it in their 121 with their team

Job shadowing can provide great results because it gives team members insight into each other's day-to-day work. I've found that when you see how someone from another team navigates different challenges and priorities, which you're not always privy to, that can build empathy and respect. And then that opens up a space to talk about how we can work together more effectively.