This is so insightful and well thought-out thanks!
I can't think of anything else to add to pros.
In terms of cons, here are my thoughts:
- sector-focused firms would have harder time finding appropriate markets when it comes to international expansion. They are limitted to countries with strong industries and large client base that align with their sector specialism. (But I guess the pros would be that having a shared goal across the international network help to streamline internal management, facilitate decision-making and boost staff morale that is neccessary to retain partners at managerial levels)
- there are higher risk of conflict of interest as they act for clients in the same industries, who may find, or will find themselves on opposite ends of a case/deal. They might be forced to give up clients in the even such conflict arises (I'm not quite sure on this point, please correct me if I'm wrong...)
To build on the point you made about large firms who are good at a lot of things, the reason to not go sector-based is probably because they don't want to limit their flexibility to move into different markets. When large firm expand overseas, they often structure practice strengths and priorities accordingly to the geographical demands, rather than letting their specialisms dictate their strategy. For instance, while
Herbert Smith Freehills reputation lies particularly at its dispute resolution expertise, there is relatively little use of this in Malaysia where international law firms is precluded from giving advice on Malaysian law. Rather, the firm must demonstrate its experience and thought leadership in Islamic finance, which is neccessary to acquire license to establish office in Malaysia.