Re: Two appended arrays aren't creating the same, pics below.
Hi @Anonymous
I am not 100% sure about your differences but I can tell you that there is an easier way to create an array. I do note that your values should be in double quotes though "", which might be part of the problem.
Assuming your first array is using list files as the source, you can use select action.

Your 2nd array is a bit more complicated as I cannot see the source and you have a counter. A counter can be achieved by using the range expression and I have based the example below on the value array from get files once more, but you can update to your actual source. If you want to include the
FROM: range(0,length(outputs('List_files_in_folder')?['body/value']))
MAP: outputs('List_files_in_folder')?['body/value']?[item()]?['NameNoExt']
KEY: File_Name_add(item(),1)
Above I have dynamically included the number in the key name:

Output is as follows (but you would have the dynamic add(item(),1) in your value parameter

I've a couple videos on my YT about array manipulation - worth a watch if you are new to it all. Any q's just ask.
If this post helps, then please consider Accept it as the solution to help the other members find it more quickly.
Cheers,
Damien
P.S. take a look at my new blog here and like & subscribe to my YouTube Channel thanks 😉