Let’s get this out of the way up front. The least expected new entrant to the Global 100, Gowling WLG, is going to have to work very hard to avoid being the classic 2 + 2 = 4 union when its tie-up goes live in January. Yes, it’s hard to see much downside given the hand WLG was playing, after a necessary and credibly integrated union between Wragge & Co and Lawrence Graham last year. The Gowlings fit is close enough to be acceptable, if not beyond debate. But the relative lack of interaction between the UK and Canadian economies, and the awkward realities of a dual-hub structure mean it will be perilously easy to settle into two firms existing under the same brand, rather than becoming more than the sum of its parts.