It's pretty easy to pull up a window of all Accountant-related tasks whilst still filing all waiting-for items under Waiting and non-waiting person-related items under People:

• Command-2 to your Context mode
• Command-click People/Accountant
• Command-click Waiting/Accountant
• Control-Command-P to open the Perspectives menu
• Moan about the lack of a "Save Perspective As..." option
• Click + to create a new Perspective
• Click the camera icon to snapshot the Perspective

From then on, you can visit the Accountant perspective and see all the items.