Without getting the proper references; I believe that a good proportionate of deals (50%) of those that fail are due to culture fit in some degree.
Strangely there is no enough that executives do about it. Probably because in the absence of a deal, very few companies and executives focus on management of culture. So the question then is; why bother when doing a deal. So until we can prove the value of culture on a standalone value; it will be difficult to articulate the value of culture in a deal.