Know-How Exchange : Branding

Like so many things, the answer is "it depends." It depends on the industry segment, the specific companies involved, perception of the various customers and target audiences, current brand positionings, etc. As you note, this is a unique situation, so there is no precedent for THIS particular decision.

This sounds like a case for an experienced and objective branding consultant who can deep-dive the situation and provide a well-reasoned recommendation. This is not a decision you want to make based on some suit's opinion, or the "shiny new object" in the form of a well-known brand.

If 'A' is a competitor of 'B', then it may make sense to rename as 'B' or 'A-B', based on the name recognition (how would A's customers feel if A seemingly disappeared?). If A and B are unrelated, then it combining names may be a detriment. This is not a decision you'd undertake lightly or off-the-cuff.

I have personal experience with this and the truth is: some people in Company A where thrilled and some where not. Some of the troubles that arise come later; sometimes months, years after the merge. No one in Company B was happy because they felt like their jobs were at stake. The real issues come from customers of Company A who feel neglected and often suffer the most in a transition such as this. Consumers don't care what a company bottom line is but they do care how any change is going to impact them. In my case, the customers resented not being taken into consideration when Company A branding went away; they had nothing left to identify. Be careful. Consultant an experienced and objective banding consultant. Do focus groups; test the waters.