It isn't necessary to pay much attention to the Task ID numbers as you arrange and rearrange the Tasks on the drawing page. The Renumber Tasks button on the TaskMap Toolbar makes it very easy to apply new numbers to one, a few, or all Tasks on the page at any time.
Another advantage of this approach becomes apparent when you begin to edit a TaskMap. You may find that some of the Tasks you've added to a page actually belong in a different place on the page or on another page, or you may end up deleting some Tasks altogether. If you've taken time to keep all the Task IDs correct, your time has been wasted.