I was fortunate enough to meet with the senior partners of two companies last week, one a corporate financier and the other a large law firm. The firms had been through recent mergers, hugely increasing their international footprint and the range of services they offer. 

Both reported that their effective earnings per fee-earner had risen strongly because they were able to compete for much larger deals and clients.

Similarly, the discussion referenced below at the Legal Marketing Association in Atlanta last week strongly suggests that larger clients are looking to use a smaller number of suppliers with a broader range of services, again suggesting that bigger is better. 

However, size is not the story here, the benefits were aligned with diversity; size is a necessary bi-product (potentially even an unwanted one). What clients are looking for is breadth, whether that be geographical or human. 

On a similar vein, the FT has published a good article (paywall) "Can you be a mother and a senior law firm partner?" which looks at the efforts being made to address the gender imbalance (and hence lack of diversity) at the top of large legal firms. 

I was particularly taken with the idea Tom references below of it taking a "village" to service a client, with many specialists each with separate roles to fulfil. It is interesting though that whilst a village has plenty of different experts, it's not a town, let alone a city.