The Project: I have several cases where I'm not sure whether or not I should be using a 'Separation of Concerns' approach or a simplistic one. They're all similar to the setup below.
Estimate contains multiple
EstimateController.Details -> Displays the details of an Estimate (Name, Description, Etc.) and below that it displays a tabular view of Notes (separated by type).
On one hand, it would be a separation of concerns and creating a new controller sounds like the proper way to do things, making use of partial views if necessary.
On the other hand, it seems a bit like overkill to have a controller for all the cases like this. (i.e. Estimates contain: Notes, Specification Numbers, Drawing Numbers, and Addendums. This is similar to multiple other models in the business model as well).
I've found many places saying that you should have a separate controller for each view model but out of the ones I've seen none of them mention why or mention how trivial of a model is too trivial?