Position numbers for custom fields only refer to relative position among the custom fields. All of these, by design, are placed below the main body of the form. If you want them somewhere else, you’ll have to create custom themes and do your own coding in Liquid.
You mention fields you want, but don’t say what those are. Basically, the fields displayed on any given form are most of the fields available and associated with that form. I say most because, for example, taxes are calculated on a line-item basis but only displayed on a total basis. So there may be somewhat more data than you see. What is your use case?