When I have worked with scaling Scrum over several teams (up to 10 in parallell), I have strived to strengthen the same processes that gives traction to a single team.
Alistair Cockburn compiles this beautifully in his Software engineering in 21:st century
People issues determining a projects speed
- Can they easily detect something needs attention? (Good at Looking Around)
- Will they care enough to do something about it? (Pride-in-work; Amicability)
- Can they effectively pass along the information? (Proximity; face-to-face)