> But what I still don't understand is that some json
  > outputs I see have multiple values with the exact same name

This is neither explicitly allowed nor explicitly forbidden by the JSON spec. It is implementation dependent upon how to handle - does one value override the other? Should they be treated as an array?

In practice, this situation is usually carefully avoided by services that produce JSON. If you are interfacing with a service that does produce duplicate values, I'd be interested in seeing it for curiosity's sake. If you are writing a service and this is the output, then I implore you to reconsider!

You might be missing a change in index: `obj[0].prop` vs `obj[1].prop`. Or, your JSON might have the same property defined multiple times: `{a:1, a:2}` (though I'm not sure how gron handles that situation).

> (though I'm not sure how gron handles that situation).

It seems both gron and jq only use the value that has been defined last:

  ~  echo '{"a":1,"a":2}' | gron                                                                                                                                   
  json = {};
  json.a = 2;
  ~  echo '{"a":1,"a":2}' | jq                                                                                                                                    
  {
    "a": 2
  }

The json output likely contains multiple objects. Can you request more specifically the object(s) you need and grep on that?