The implemented is very easily:

public class ExtendableLocalDataSourceFieldDescriptionsProvider : LocalDataSourceFieldDescriptionsProvider
{
    protected override ContainerNode GetFieldDescriptionHierarchy(IEnumerable<IPivotFieldInfo> fieldInfos)
    {
        var infos = from info in fieldInfos
                    orderby info.GetDisplayAttribute()?.GetOrder()
                    select info;
        return base.GetFieldDescriptionHierarchy(fieldInfos);
}

We will be glad to get it out of the box for all data providers.