Ignore this comment

You could use xquery to get the position and use the attribute in the JSON updater?

So XMLXQueryExtractor

let $json_doc := fme:get-json-attribute("NE_JSON")
let $processors := jn:members($json_doc("flowContents")("processors"))
return (
    fn:index-of($processors("name"),"Build-Parameters")
)

Then use the created attribute containing the index in the JSONPath in the JSON Updater

I suspect you could do the entire replacement using XMLXqueryUpdater

ebygomm, I went ahead and marked your answer as the best answer. I think you are correct and this could all be accomplished in XMLXqueryUpdater. 

I did have a few reasons I had chosen JSONUpdater. 1. I really liked the JSONUpdater dialog box for listing the individual changes to the document. Makes it easier for someone after me to see everything that I was changing. 2. I’m not good at Xquery (or JSONIq hence post), but going back to #1 and trying to find JSONiq solution seemed to fit using JSONUpdater. 3. I did initially solve this with simple AttributeManager and doing sting replace for values. But it started becoming complex as I couldn’t control all the values I was trying to replace. So moved to using JSONUpdater. 

In the end I liked the JSONUpdater dialog box so much I wrote a very simple Python script to sort order the processors by name. Then I could always reference the order number. 

self.data = json.loads(feature.getAttribute('NIFI_JSON_TEMPLATE'))
processors = self.data.get("flowContents", {}).get("processors", [])
sorted_processors = sorted(processors, key=lambda x: x.get("name", ""))
self.data["flowContents"]["processors"] = sorted_processors
feature.setAttribute("NIFI_JSON_TEMPLATE", json.dumps(self.data, indent=2))
self.pyoutput(feature)

Sorting the json with python sounds more complex and less supportable to me than getting the position with xquery and then using that as the index in the JSON Updater but glad you got it sorted.