I have changed the name of the view_template, but it is not changed in the name of the template.
How can I make this 'loop' use an existing template that has created a different 'loop'?
Hello. Thank you for contacting the Toolset support.
Well - When you edit your archive view, within the Loop Output editor you will find button "Content Template", simply click on that button and you will know further what to do. Please check following screenshot.
=> hidden link
Well - I see "Loop item in View-For-Blog" content template is already assigned to another view and that is the reason it's not displaying withing the dorpdown select box when you click on "Content Template" button.
Now, I would like to know, did you use "Loop Wizard" button to build your output?
Well - As you used "Loop Wizard" the only way to remove current content template is you need to run loop wizard again and make sure you do not create content template using loop wizard.
So basically, when you create content template using loop wizard it will not allow you to add at multiple places so create individual content template and then add to multiple views as required.