Yes, that is right. Some of the project management costs—in fact, the vast majority of project management costs—are costs incurred by government departments that relate to the management of their projects. I don't know the extent to which these are incremental costs versus costs that would have been incurred anyway. I doubt that, to be honest.
This is consistent with estimating methodologies of other budget institutions across the world. It's consistent with budget estimates for other big procurement projects, such as the surface combatants, the CF-18s and so on.