Duplicate rows created during featureset generation

[Blevins_Mark]

I am using the following code to take two layers and merge into one table as a featureset.

//import
var portal = Portal('myportalurl');
var permitboundary_fs = FeatureSetByPortalItem(portal,'0ec1d6d3b5424618a0ac08129f7ac045',0,['name','area_acres'],false);
var disturbancearea_fs = FeatureSetByPortalItem(portal,'923a817eedd242d1af359a0963c6e9b0',0,['permitname','area_acres'],false);

//groupby
var permitboundary_final_fs = GroupBy(permitboundary_fs,'name',[{name: 'acrecalc', expression: 'area_acres', statistic: 'SUM'},])
var disturbancearea_final_fs = GroupBy(disturbancearea_fs,'permitname',[{name: 'acrecalc', expression: 'area_acres', statistic: 'SUM'},])

//create dictionary
var fsDict = {  
    'fields': [
      {'name': 'permit_name', 'type': 'esriFieldTypeString' },  
      {'name': 'permit_acres','type': 'esriFieldTypeInteger'},
      {'name': 'disturbance_acres','type': 'esriFieldTypeInteger'},
    ],
    'geometryType': '',   
    'features': []
  };

var index = 0

//loop to populate dictionary
for (var permitboundaryfinalfeat in permitboundary_final_fs) {
    fsDict.features[index++] = {
      'attributes': {
        'permit_name': permitboundaryfinalfeat['name'],
        'permit_acres': Round(permitboundaryfinalfeat['acrecalc'],0)
      }
    }
}

for (var disturbanceareafinalfeat in disturbancearea_final_fs) {
    fsDict.features[index++] = {
      'attributes': {
        'permit_name': disturbanceareafinalfeat['permitname'],
        'disturbance_acres': Round(disturbanceareafinalfeat['acrecalc'],0)
      }
    }
}

return FeatureSet(fsDict)

When i return the featureset it duplicates the area names and populates values for the second attribute, rather than just populating the records created during the first for loop. I think i need a if statement in the second for loop bur not sure of the syntax?