There is not a way to automate the output of the view and then have Tableau read these in automatically. It's a great idea though so maybe consider adding it here: Ideas
There are a couple of ways to approach this:
1) Build a data preparation process to do the summarization and preparation. This can be done with Microsoft SSIS, data prep tools like Alteryx or Trifacta, Python, R, etc.
2) If you're using Excel files then the data volumes are almost certainly not "large" in the Tableau sense and there is likely little to no need to do a pre-summarization before using the data in Tableau...in fact what I see again and again is people starting out with Tableau by connecting to summarized data (such as from a cube) and then pretty soon they want a lot more detail and have to think about their data pipeline.
Therefore my suggestion in this case would be to use a union across sources in a single workbook so instead of needing 3 workbooks you can have one. If you can't use Tableau's built-in union functionality (for example when unioning an Excel source to a SQL Server source) there are workarounds, I documented one at Cross Data Source Joins + Join on Calcs = UNION Almost Anything in Tableau v10.2 | Drawing with Numbers .