That's a genuine pattern, yes. But the consultant should also ask if they have any particular concerns that require a deep dive? For example they may know of security weaknesses or geodatabase health problems. There could be specific performance issues, that need further investigation as well.
A common topic at the moment is, the cloud, and if the existing environment is fit for migration and best strategies to that. This latter discussion should also consider Kubernetes, if the scale of the current solution aligns.
I normally allow for around 2 weeks, but if further investigation in a specific area is required then that may expand to 3.
Scott Tansley
https://www.linkedin.com/in/scotttansley/