To put it clearly, introducing microservices without creating domain-focused teams does not lead to the main benefits meant to be derived from microservices. It is always problematic to implement only some parts of a certain approach as only the synergies between the different parts will generate the overall value. Although implementing microservices without domain-focused teams is a possible option—it is certainly not recommended.
As already discussed in section 12.7, the microservice structure should ideally extend to the departments. However, in reality this is sometimes hard to achieve since the microservice architecture often deviates too much from the organizational structure of the departments. It is unlikely that the organization of the departments will adapt to the distribution into microservices. When the distribution of the microservice cannot be adjusted, the respective product owners have to take care of prioritization and coordinate the wishes of the departments that concern multiple microservices in such a way that all requirements are unambiguously prioritized for the teams. If this is not possible, a collective code ownership approach (section 12.2) can limit the problem. In this case the product owner and his/her team can also modify microservices that do not really belong to their sphere of influence. This can be the better alternative in contrast to a coordination across teams—however, both solutions are not optimal.