Don't rely on version control to handle it. Automation in general is replacing JUST TALKING TO THE OTHER PEOPLE WORKING ON YOUR PROJECT and is one of the FASTEST ways to suck the quality -- and humanity -- out of the process.
There is an over-reliance on tools and an under-reliance on communication that is gutting the quality and sustainability of software projects of all sizes. Pick up the phone or GOD FORBID get off your arse and walk across the hall and TALK to the other people working on it. Establish code "provinces" and delegation of tasks instead of blindly hoping that multiple people working on the SAME PIECE OF CODE is going to somehow magically work!
In that way, modularization and proper management can go a lot farther than any stupid tool can. Divvy up the tasks, give each member of the project subsections that speak to their specialties and skillsets, and if they need to tread the line out of their assigned zone for something, ACTUALLY HAVE THEM TALK TO EACH-OTHER!!!
... and yes that means more work for the person in charge, that's why it's called work and not "happy happy fun sexy time"