Architecture enforcement is concerned with the correct and seamless implementation of architecture design decisions in order to ensure software quality. In a previous study, we conducted an empirical study in order to gain insight into the industrial practice of architecture enforcement. There, we asked 12 software architects from industry about their experience with the architecture enforcement process. As a result, we identified architecture enforcement concerns and activities. In this paper, we extend our contributions of the existing study. Firstly, we conducted five additional interviews with software architects from two different domains, namely the enterprise application and the automotive domain. This adds new architecture concerns and activities to the existing list. Secondly, we conducted a literature review. We compared our findings from the interviews with the results from the literature review and evaluated how architects' enforcement concerns and activities are discussed in literature. We found that several concerns and activities are already known from literature, but are not viewed in the context of architecture enforcement by the software architecture community. Lastly, we connected the discovered architecture concerns and activities with each other. Those relationships determine the reason why a specific architecture enforcement activity is conducted.