"it would be far more productive for all of them to work together" -> not necessarily. It's not very common but there are examples of having multiple teams try

"it would be far more productive for all of them to work together" -> not necessarily. It's not very common but there are examples of having multiple teams try to solve the same problem in parallel. It ends up speeding up development - they will come up with different approaches, and the best (or a combination) can be selected.