There is a classical monkey intelligence test, where you put a monkey into a room with a banana hanging from the ceiling and some boxes spread on the floor. Can the monkey figure out to get the banana by putting boxes on top of each other?
Scaling agile is a lot like putting scrum teams on top of each other.
A more viable approach would be to lower the ceiling so that no boxes are needed. I.e. chaning the environment and the conditions of work so that agile becomes possible at a reasonable scale.
Just a thought.