Who are the best consultants to support post-merger integration on large, complex, international deals? Does McKinsey, Bain, BCG, or the Big 4 (Deloitte, PwC, etc.) offer any particular expertise that differentiates one from another?
MBB and Big Four are really big players in Consulting industry. However, they may not be necessary good to support post M&A integration. Some of the local bontique consulting firms are very good (or niche) in particular industry, it means that they have strong domain knowledges to support post M&A integrations of corresponding industries.