git is overkill for facilities with small groups working in a common area (not hard to imagine if you're in the hardware biz) and all the engineers are used to cvs command syntax..
The only thing I would not use version control is if you have files that don't change. Everything else should be in some form of VC (sometimes Git is not the best choice, but it's good for lots of things)
In my estimate, Broadcom is on the cusp of reaching a sublime point I've seen in other, unnamed semiconductor companies, at which the number of combinations and revisions of IP within a family of chips becomes difficult to account for.
So, it's really not even a question of git being overkill - it's a question of whether its source code will persist over many times the length of the proejct. Git will be considered for substitution by those deeply committed to CVS simply after a matter of time, once its institutional bugs have been discovered and patched.
You don't have to have a distributed workflow to occasionally reap the benefits of working with git.
Hey, I like git too. Respecting the needs of others not to spend mental load on learning something they don't want to is often important too.
Is it really worth it to spend time re-training the 15/20 engineers that don't already know git? I don't think so.