已自行解決，
發完後隔天突然想到，我index排序後，stage跟著重新排序即可。

各位好，如下圖，
第一次刪除的時候，stage會正常-1
但是我刪除第二次的時候，就會錯亂。
請各位幫我看一下，邏輯應該要如何修改?
Delete Item內部功能是，
當我delete單一列時，該列後面的stage比較大，stage 要-1
然後再刪除該列。
最後在重新排序表單上的row，排序後資料新增才不會有誤

@model PoProcessViewModel
<form method="post" action="/Home/editPoFLow">
    <h3>Sign Flow</h3>
    <button type="button" class="btn btn-primary" onclick="AddRow()">Add Row</button>
    <br />
    <table id="signTable">
        <thead>
            <tr>
                <th>Sign Name</th>
                <th>Stage</th>
                <th>Price</th>
                <th>C Name</th>
            </tr>
        </thead>
        <tbody>
            @for (int i = 0; i < Model.poSigns.Count; i++)
            {
                <tr>
                    <td><input type="text" id="poSigns[@i].signname" name="poSigns[@i].signname" class="form-control" value="@Model.poSigns[@i].signname" /></td>
                    <td><input type="number" id="poSigns[@i].stage" name="poSigns[@i].stage" class="form-control" value="@Model.poSigns[@i].stage" /></td>
                    <td>
                        <select class="form-select form-select-lg" id="poSigns[@i].price" name="poSigns[@i].price">
                            <option value="-1">-1</option>
                            <option value="5000000" selected="@(Model.poSigns[i].price == 5000000)">5000000</option>
                            <option value="15000000" selected="@(Model.poSigns[i].price == 15000000)">15000000</option>
                        </select>
                    </td>
                    <td><input type="text" id="poSigns[@i].cname" name="poSigns[@i].cname" class="form-control" value="@Model.poSigns[@i].cname" /></td>
                    <td>
                        <button id="btnremove-@i" type="button" class="btn btn-sm btn-danger visible" onclick="DeleteItem(this,@i)">Delete</button>
                    </td>
                </tr>
            }
        </tbody>
    </table>
    <input type="hidden" id="hdnLastIndex" value="0" />
    <input class="btn btn-default" type="submit" value="儲存" />
</form>
<script type=text/javascript language=javascript src=https://code.jquery.com/jquery-3.7.0.js></script>
<script>
    function DeleteItem(btn, index) {
        var stageValue = $('#poSigns\\[' + index + '\\]\\.stage').val();
        var rows = $('#signTable tbody tr');
        // Check if there is a larger stage value
        var hasLargerStage = false;
        for (var i = 0; i < rows.length; i++) {
            var currentStageValue = $(rows[i]).find('input[name^="poSigns["][name$="].stage"]').val();
            if (currentStageValue > stageValue) {
                hasLargerStage = true;
                break;
            }
        }
        if (hasLargerStage) {
            // Subtract 1 from larger stage values
            for (var i = 0; i < rows.length; i++) {
                var currentStageElement = $(rows[i]).find('input[name^="poSigns["][name$="].stage"]');
                var currentStageValue = currentStageElement.val();

                if (currentStageValue > stageValue) {
                    currentStageElement.val(currentStageValue - 1);
                }
            }
        }
                // Update the index of remaining rows
        rows = $('#signTable tbody tr');
        for (var i = 0; i < rows.length; i++) {
            var currentRow = $(rows[i]);
            currentRow.find('input[type=text], input[type=number], select').each(function () {
                var name = $(this).attr('name');
                $(this).attr('name', name.replace(/\[\d+\]/, '[' + i + ']'));
                $(this).attr('id', name.replace(/\[\d+\]/, '[' + i + ']'));
            });
        }
    }