A topic branch workflow is tremendously useful even without separate people in the "developer" and "integrator" roles. For example, we have about 20 people regularly developing code and about five of us "integrate", first to 'next', then to 'master' when a feature has stabilized. We don't explicitly pass an integrator token so there is a possible race to the integration branch, but since we only merge there, it's actually pretty rare in practice. If you lose the race, the polite thing to do is discard your old merge, fast-forward, and repeat the merge. This preserves first-parent.

http://git-blame.blogspot.com/2012/03/fun-with-first-parent....