One of the hardest part of mobilization is to get momentum so that you can get the different projects / workstreams up and running. At this critical phase, the last thing on the sponsors and program managers mind is getting the right tools and governance in place.
This creates a problem for the PMO. It is important to embed robust tools, processes and governance. However, during mobilization, there is so much that needs to be done that everyone wants to focus on mobilization activities and for the formal aspects of PMO management to catch-up.
The big risk is how do you know that you are mobilizing quickly enough, the right items are being delivered, sufficient controls in place and transparency to allow rapid intervention to get a project / workstream back on track?