In college, I studied the failed merger between GM and Ross Perot’s Electronic Data Systems (EDS). Essentially a study on egos and cultural incompatibilities.

https://www.nytimes.com/1989/03/26/magazine/gm-vs-ross-perot...

Sadly, no. It was over a decade ago. I don’t remember the cases nor do I have the books or paperwork.

Fortunately, case studies are really easy to find online. Try searching for “case studies in brand management”.