Word 2011 for Mac users can change the ribbon tab order using customise ribbon tab order option available as part of the Office Ribbon. For example if you are frequently using the SmartArt feature then it make sense to move the tab ahead of other tabs.
Step 1: Click the Settings option available at the end of Office Ribbon and select Customise Ribbon Tab Order option.
This should make the tabs movable and allow the users to rearrange the tabs
Step 2: Now you can drag and drop the SmartArt tab ahead of other tabs and place it after Home tab.
Step 3: After changing the tab order, click Done button to confirm and apply the changes.
And if you want to revert the current changes to the default tab order settings then click the Reset button.