Not sure if your laws are like ours...but id guess they are...in which case, you will want to be sure that the method of security is clear if they come under a different category...
For example, if one safe is attached to building, & the other safe is 150 plus KG's. and both of those come under a different category, then be sure & tick both category's, &/or notify the relevant authority that you now have 2 different methods of securing firearms.
Having said that, it is only an example, i cannot be sure of the different categories at the moment without looking them up...which im not going to do...
Not sure if being clear or not...
The man who knows everything, doesnt really know everything...he's just stopped learning...