OK, let me be blunt:  AmLaw 200 firms are simply too large and too complex enterprises to be managed with any less professionalism and strategic and financial acuity than equivalent-sized corporations.  (These days, "equivalent-sized" means about $200-million in revenue, at the mean.)

So when considering overseas expansion, say, to London, would one not scrutinize:

• the hard-headed business case for going there;
• client-centric or practice-group opportunities;
• the break-even calculation;
• the legal status of the London office (four choices:  UK partnership, UK LLP, US partnership, US LLP, each with different tax and regulatory/disclosure consequences); and, not least;
• cultural considerations.

The article I linked to is worth a read for the these considerations:  Alas, its tone is supercilious towards US firms' establishing London outposts and it claims, with breathtaking ignorance of or obtuseness towards the actual track record, that "US firms setting up in London eventually fail."   Its managerial recommendations, then, I endorse; its weirdly xenophobic attitude, I do not.