Special sort required

Attached is an attempt with VBA. Backup your file first before you using the Code. The code is untested.

Sub ScrambleTeams()
    Dim Teams As Variant
    Dim i As Integer, j As Integer
    Dim Games(1 To 4, 1 To 8) As Integer ' 4 Games, 8 Numbers
    Dim UsedNumbers As Object
    Dim RowOffset As Integer
    Dim RandomIndex As Integer
    Dim Temp As Integer

    ' Define the team numbers (adjust as needed)
    Teams = Array(1, 2, 3, 4, 5, 6, 7, 8) ' Adjust for 16 if needed

    ' Shuffle the teams randomly
    For i = UBound(Teams) To 1 Step -1
        RandomIndex = Int((i + 1) * Rnd)
        Temp = Teams(i)
        Teams(i) = Teams(RandomIndex)
        Teams(RandomIndex) = Temp
    Next i

    ' Create unique pairings for 4 rounds (rows)
    Set UsedNumbers = CreateObject("Scripting.Dictionary")

    For i = 1 To 4 ' 4 games
        UsedNumbers.RemoveAll ' Clear previous round's numbers
        RowOffset = (i - 1) * 2 ' Shift by 2 rows for each game

        j = 0
        Do While j < 8
            RandomIndex = Int((UBound(Teams) + 1) * Rnd) ' Get a random index

            If Not UsedNumbers.exists(Teams(RandomIndex)) Then
                Games(i, j + 1) = Teams(RandomIndex)
                UsedNumbers.Add Teams(RandomIndex), True
                j = j + 1
            End If
        Loop
    Next i

    ' Output results to Sheet1 (adjust as needed)
    With Sheets("Sheet1")
        .Range("A1:H4").ClearContents ' Clear old data
        For i = 1 To 4
            For j = 1 To 8
                .Cells(i, j).Value = Games(i, j)
            Next j
        Next i
    End With

    MsgBox "Teams Scrambled Successfully!", vbInformation
End Sub

My answers are voluntary and without guarantee!

Hope this will help you.

Happy Excel-ing!