Объединить листы excel в один

Option Base 1
Sub copyUnion()
Dim firstBook As Workbook
Dim secondBook As Workbook
Dim thirdBook As Workbook
Set secondBook = ActiveWorkbook
Set firstBook = Workbooks.Open("C:\\ALL.xlsx")
Set thirdBook = Workbooks.Open("C:\\File.xlsx")
Dim mass(1099, 2)
For i = 1 To 1099
    For j = 1 To 2
        mass(i, j) = firstBook.Sheets(1).Cells(i, j)
    Next
Next
secondBook.Sheets(1).Activate
secondBook.Sheets(1).Range("A1:D31673").Copy
thirdBook.Sheets(1).Activate
thirdBook.Sheets(1).Range("B1").Select
ActiveSheet.Paste
thirdBook.Sheets(1).Range("B1:B31673").Copy
thirdBook.Sheets(1).Range("A1").Select
ActiveSheet.Paste
For i1 = 1 To 31673
    For k1 = 1 To 1099
        If thirdBook.Sheets(1).Cells(i1, 1) = mass(k1, 1) Then Cells(i1, 1) = mass(k1, 2)
    Next
Next
End Sub

Sub copyUnion()
Dim firstBook As Workbook
Dim secondBook As Workbook
 
Dim ws1 As Worksheet
Dim ws2 As Worksheet
 
Dim i, i1, j, j2, s1, spath, dt1
dt1 = Timer
spath = Excel.ActiveWorkbook.Path & "\"
Set secondBook = ActiveWorkbook
Set firstBook = Workbooks.Open(spath & "file1.xlsx")
Set ws1 = firstBook.Sheets(1)
Set ws2 = secondBook.Sheets(1)
 
Dim mass(200000) As Long
For i = 2 To 200000
     j = ws1.Cells(i, 1)
     If j > 0 Then
     mass(j) = ws1.Cells(i, 2)
Else
Debug.Print i, ws1.Cells(i, 1)
End If
Next
 
 
 
For i1 = 2 To 31673
j2 = Val("0" & ws2.Cells(i1, 1))
If j2 > 1 Then
    s1 = mass(j2)
    If s1 > 0 Then
      ws2.Cells(i1, 6) = s1
    Else
      ws2.Cells(i1, 6) = "Empty"
      Debug.Print i1;
    End If
    End If
    Next
    Debug.Print
Debug.Print "время выполнение="; (Timer - dt1) \ 1; " sek"
''21sek
''надо доработать для объединенных ячеек
End Sub