I think it’s more relevant to the size of the company. Large companies have the capability to have large teams that include design strategists (or outsource to a firm that does). Small companies rely on fewer people to do the same job. I don’t really believe one way is right or wrong, you have to do your best as a company or individual no matter your resources. Design strategy, to me, is an elevated view of the entire business model and industry from a creative perspective. It’s traditionally something business minded executives or high level managers are responsible for. I have worked mainly in small companies and this type of thinking is a large part of what I do, although not my title.
The bottom line to me is, designers feel threatened by those who don’t create but call themselves designers. A more fitting title for the Design Strategist would be Business Strategist or Product Strategist, ultimately more descriptive of what they do.