It is also seems true that CM is rarely invited into the early planning phase of a product's development where they could provide insights into how to make the development process easier on development. I wish I could give a pithy or succinct pointer on how to resolve this, but I have been fighting it for more than three decades and it seems to still be one of the more common questions asked. All I can suggest is trying to capture some statistics on the time lost due to “unnecessary” merging and duplicate documents (or replicated document “pieces” that have to be independently maintained) and use them to convince management to involve CM before the next product is started.
Finally, while it is true that you can use software CM tools to perform hardware CM, it is generally not practical. Just like management likes to “right size” personnel, use the right tools to do the job.