Hiring more people does help but there will still not be 40 hour work weeks. In many instances, some people in the team has built up the knowledge on a particular part of the deal that it is difficult to outsource since it would be much faster for the person to complete the work themselves.
Hiring more people also means that the information is diffused around. If one person working on a deal it means that he knows 100% about the deal. If 100 people is working on the same deal, efficiency would greatly decrease as knowledge management becomes important (lots of emails).