Is it possible to configure TFS 2015 in order to have:
1 project in which different teams are working under BUT are using different versions of source control.
The structure we are aiming for is something like what is described in this blog post. Essentially one project for the entire company, with teams slotted underneath that.
Say company CyclingAwesome has two teams working under the project: CyclingAwesome.
Will Team A be able to configure TFS to use Git (say they run the website) - and then at the same time, will Team B be able to configure TFS to use TFS source control (say they have backend processes)?
How does this affect setting up automated builds for either team?
This is available as part of TFS 2015.1, it is live in VSTS at the moment, if you want to experiment.
The workflow only supports the addition of Git repositories to a Team Project with TFVC to start with, not many people go from Git back to TFVC ;).
With XAML builds, there are 2 templates (one for TFVC and one for Git), just select the one you need to build your teams code. With Task (vNext) builds you can select the Source Control provider as part of the repository options.