Feature request from stasleo, posted on GitHub Apr 14, 2016
There is no way currently to specify sort order for tabs added by module at frontend product page. Magento2 just loads tabs from A to Z by its module name.
For example, our extension adds "Product Questions" tab to a product page: http://magento2pq.demo2.aheadworks.com/cassius-sparring-tank.html
Its position is 1st and there is no any attribute to place it at some other position. It is obvious that most of our clients would prefer to make "Description" tab appearing first.