Transferring within Google is easy. Yes, you would be expected to stay on your first project for a reasonable chunk of time, but transfers after that are not only possible but expected.
How do you reconcile that with your claim elsewhere that "staff turnover is very very low?"
I worked in the Mountain View office. Transferring is indeed easy, and people did transfer frequently. As a result turnover was high, and it was hard to build friendships, or gel as a team.
