Let me give an example. Although when you segment your network , and even segment your configuration , although overall network might be a more complex from the management complexity point of view due to more configuration and protocols usage.
But on the other hand, you simplify individual tenant configuration. For example you can configure VRF ( Virtual routing and forwarding instance ) for each applicaiton/network/tenant and put them into VRF. Now managin the individual policy is much easier. This is modularity and also we call it vertical layering. Can problem still occur?.Yes it can. For this I want to point out my early NC article.