Yes, As per my opinion. When we are talking about a strategic project using a structured approach of DMAIC or DMADV, then a trained personnel is required to drive the project SLAs.
Any professional who is not being aware of methodologies to be used in any of step or situation can cause a delay or cost to the project. To take appropriate decisions in a project, one must be statistically correct and should be able to draw a conclusion to a situation.