[bluGill]

What you describe is typically an architecture problem: if you have a good architecture in place the problem won't happen because you have already broken your system up so that those places that 10 completely different developers need to touch do not exist in the first place. You need to hire more senior developers to think about this problem and fix it. You should be able to assign every area of code to a small team of developers who work together and coordinate their changes to that area. (even with common code ownership you quickly specialize just because on a large project you cannot understand everything)

There are exceptions. Sometimes there is a management problem: management has been told some things cannot be done in parallel because you couldn't mitigate the problem in architecture and they failed to apply project management practices to ensure the developers worked serially.

Sometimes there is a team problem: the 10 developers have been placed on the same team to work on the same thing, and despite all that they still failed to coordinate among themselves to ensure that the changes happened in order.