Hope this helps,
We use the T&T APIs to pull down all T&T campaign data to our EDW and then we aggregate it ourselves and create a Tableau Extract (which is refreshed on each successful ETL process). We then pull those extracts into a Tableau report that is automated and filtered on campaign ID so we can view any/all test data, mixed with our DW data in a Tableau report. You could use Tableau to aggregate all of your campaigns into one report (using the filters option).
As far as I know there is no option to automatically pull in Adobe tools as a data source (like there is with Google Analytics, for example). I believe this integration was announced to happen a few years ago but it doesn't seem like anything ever came about. Would be great (and not that tough) to have the Target team build an integration with a great reporting tool like Tableau.
Apologies for the delay in responding. Adobe Marketing Cloud Community is the place to get help, advice, tips and tricks, and network with other people using Adobe Marketing Cloud solutions. I'd be more than happy answer any specific queries around Target if you have any.