The main drawback
There is one main drawback of validating the data this way. The problem will not occur until you try to post. An example would be when we have to post a shipment; the shipping agent is waiting with his truck and Dynamics NAV throws an error message because someone up the chain didn't properly do their job.
Problems like this can be mitigated by setting default values to the mandatory fields through modifications or through templates. However, the company should have the proper process or guideline in place for people to follow; the users should be responsible for their work. Basically, accountability is required.
In a way, this "drawback" is a benefit because there's no place for people to hide. Mistakes are reflected in a relatively short timeframe within your organization and you will be able to weed out who's good and who's not.
In our case, if the truck leaves and the warehouse person has to fill in the paperwork manually, you can...