Hogan Lovells is, as of Saturday, a reality — a 2,500-lawyer, 47-office megafirm that spans four continents.

Now, the firm’s leaders have to manage their leviathan and clean up mass of details still facing them: Can they work out their compensation system? Can they build their corporate and finance practices into true power players? Can they forge a culture across a firm with this many lawyers in this many countries?