A find on the Home Page will assist the missionary's efficiency when supporting guests.
From the home page, the Family Tree menu is available, and that menu contains the Find option. So with two clicks you will be doing a find. The home page already has a lot going on (I would argue it's already too busy), so adding yet another option to save just one click doesn't seem worth the additional complexity.
Since you mention supporting guests as a missionary, I assume that you are looking for an efficient way to quickly get to a profile page the guest has a question about. I would imagine the guest would always have the ID number for that page. One very fast way to get there from the home page is to just click on Recents:
Type the ID number in the box, click Go, and you will jump right to the page you want.
The screen is a little deceiving in that the wording implies this box is only for recently viewed people. While that is true for entering a name, you can put in any ID and go to that page.