Use the same sorting everywhere

app/controllers/error_template_attributes_controller.rb

@@ -9,7 +9,7 @@ class ErrorTemplateAttributesController < ApplicationController
   # GET /error_template_attributes
   # GET /error_template_attributes.json
   def index
-    @error_template_attributes = ErrorTemplateAttribute.all.order(:id).paginate(page: params[:page])
+    @error_template_attributes = ErrorTemplateAttribute.all.order('important DESC', :key, :id).paginate(page: params[:page])
     authorize!
   end
 

app/views/error_templates/show.html.slim

@@ -20,7 +20,7 @@ h3
         th = t('activerecord.attributes.error_template_attribute.regex')
         th colspan=3 = t('shared.actions')
     tbody
-      - @error_template.error_template_attributes.order(:important).each do |attribute|
+      - @error_template.error_template_attributes.order('important DESC', :key).each do |attribute|
         tr
           td
             - if attribute.important