When displaying multiple recommender widgets on the same placement, you may need to sort these widgets based on specific order. For example, a common pattern is to display Recently Viewed recommendations at the bottom of page just before footer.
To customize sorting order, go to recommenders page and edit your recommender.
Styles > Other Config > Sort Order and modify it. Widgets will be rendered in sorted ascending order. Thus, a widget with sort order 1 will be placed above widget with sort order 3.