One of the common problems we see in our matrix management training and consulting is that matrix management is taken too far down the organization.
We worked with a financial services organization last year who wanted to implement matrix management in an organization of 1500 people. By the time we had identified the people who had purely local jobs (80 -90% of people in even the most global organizations) and the people in the middle who managed them, we identified less than 100 people where matrix management would add value and be necessary.
This is a fairly common picture, we have seen first line managers in manufacturing with matrix regional roles. Matrix management adds additional complexity, so if it does not add value it just adds cost and confusion.
Limiting matrix management is one of the key skills in a successful matrix implementation. it simplifies the structure and allows us to focus resources and attention on building the skills of the smaller number of matrix managers who really need it.