A family of Microsoft word processing software products for creating web, email, and print documents.
Unfortunately, no. Word lacks much of the Style management capabilities available in its Windows counterpart. The order is based on Priority Levels which cannot be assigned or modified in the Mac product.
Folks have been clamoring for better Style Management tools for years but little improvement has been made. You can add your voice to the choir by using Help> Feedback in the Word menu bar.
However, any custom Styles should be listed in ascending order directly beneath Clear Formatting.
Also, Custom Styles added to the Style Gallery appear first & unwanted Styles can be removed by right-clicking them & selecting the Remove from Style Gallery command..