A similar approach to what has Erica published, but with more details:

1. Export text files to a file geodatabase table;  
2. Convert those tables into dictionaries;

> polygons {41880: (26287, 26286, 26748, 26747), 41879: (26748, 26286,
> 26747, 0)}
> 
> vertices {26747: (19, 20, 21), 26748: (12, 14, 15), 26286: (13, 16,
> 17), 26287: (22, 24, 25)}

3. Building an array of polygons (each has points with XYZ values);
4. Pre-create the polygon feature class with the Z coordinates stored (important); doable with the GP tool and adding the PolyID field.
5. When loading polygons, important to specify the has_z attribute, otherwise it won't store Z-coordinates. You can see the Z-value for every vertex of the polygon when in the Editing session and having the Edit Sketch Properties window open (while editing the polygon with vertices shown);
6. As the last step, use the Join Field GP tool to transfer all other attribute fields from the Polygons file GDB table (based on the PolyID). I didn't want to take them into the dictionary just to keep things more clear.

Useful Esri Help links:
[Polygon class][1]; [Writing geometries][2]; [da.Insert cursor][3]

The ready-to-use code:

    import arcpy
    import os
    folder = "C:\GIS\Temp"
    os.chdir(folder)
    polygonsFile = "polygons.txt"
    verticesFile = "vertices.txt"
    
    outfileGDB = r"C:\GIS\Temp\test.gdb"
    
    if not arcpy.Exists(r"C:\GIS\Temp\test.gdb\polygons"):
        arcpy.TableToTable_conversion(in_rows=polygonsFile,
                                      out_path="C:\GIS\Temp\test.gdb",
                                      out_name="polygons",
                                      where_clause="")
    
        arcpy.TableToTable_conversion(in_rows=verticesFile,
                                      out_path="C:\GIS\Temp\test.gdb",
                                      out_name="vertices",
                                      where_clause="")
    
    arcpy.env.workspace = outfileGDB
    with arcpy.da.SearchCursor("polygons","*") as poly_cur:
        print "polygons"
        poly_dict = {x[1]: x[2:] for x in poly_cur}
        print poly_dict
    
    with arcpy.da.SearchCursor("vertices","*") as vertex_cur:
        print "vertices"
        vertex_dict = {x[1]: x[2:] for x in vertex_cur}
        print vertex_dict
        
    polyArray = {}
    for polykey in poly_dict:
        polynodes = poly_dict[polykey]
        coordsList = []
        for polynode in polynodes:
            coords = (v for k,v in vertex_dict.iteritems() if k == polynode)
            for coord in coords:
                coordsList.append(coord)
        polyArray[polykey] = coordsList
    
    print polyArray
    #>>>polyArray
    #>>>{41880: [(22, 24, 25), (13, 16, 17),(12, 14, 15), (19, 20, 21)],
    #>>>41879: [(12, 14, 15), (13, 16, 17), (19, 20, 21)]}
    
    features = []
    fc = r"C:\GIS\Temp\test.gdb\PolygonFC"
    
    for key,values in polyArray.iteritems():
        features.append((key,arcpy.Polygon(arcpy.Array([arcpy.Point(*value) for value in values]),
                                           arcpy.SpatialReference(4326),True))) #True - for has_z parameter
    
    with arcpy.da.InsertCursor(fc,["PolyID","SHAPE@"]) as cur:
        for feature in features:
            cur.insertRow(feature)


  [1]: http://resources.arcgis.com/en/help/main/10.2/index.html#/Polygon/018z00000061000000/
  [2]: http://resources.arcgis.com/en/help/main/10.2/index.html#//002z0000001v000000
  [3]: http://resources.arcgis.com/en/help/main/10.1/index.html#//018w0000000t000000