So what is the concern? There are three big concerns, actually. Our teacher "caution light" should start blinking if we are using lower_level_thinking worksheets (Example: "Check the box next to the correct answer."), if we are using too many worksheets or if we are using worksheets as classroom busy work.
After you create the group, the word "group" appears in the title bar of the workbook. Once they are grouped you can format one worksheet and all of the worksheets will have the same formatting. You can insert a row in a worksheet and the same row will be inserted into all worksheets. This is a great tool when you need for all of your worksheets to have the same formatting.