Re Competitors
There are two kinds-
Those who compete for the same work in a practice area or industry.
With the example of W&C, their Africa projects team will compete mainly with MC and
Latham who do work in this area.
This will be different for each practice area!
Those who are following a similar business model overall (and particularly in London).
By being bigger in London (their biggest office) W&C is pushing
Latham / Kirkland on office size, and thus is a competitor of those firms, moving to a more full service model. Equally these firms compete with established UK firms for talent and work in London. Its a very different model to a Weil for example, who focus on their core areas of expertise in London.