You can use SpreadJS and Spread.Views in the same page.

Add references to SpreadJS first. Then add references to Spread.Views.

When you reference both controls in the same project, exclude the Spread.Views gc.spread.common.12.0.0.min.js reference.

For example:

<script src="./Spread.Sheets.Release.12.0.0/scripts/gc.spread.sheets.all.12.0.0.min.js"></script>
<link rel="stylesheet" href="./Spread.Sheets.Release.12.0.0/css/gc.spread.sheets.excel2013white.12.0.0.css">
<link rel="stylesheet" href="./Spread.Views.Release.12.0.0/gc.spread.views.dataview.12.0.0.css">
<script src="./Spread.Views.Release.12.0.0/gc.spread.views.dataview.12.0.0.min.js"></script>
<script src="./Spread.Views.Release.12.0.0/plugins/gc.spread.views.gridlayout.12.0.0.min.js"></script>