All of the BKR 5000's should be able to take a clone from another. I have cloned to and received clones from NIFC BKR 5000's.
The key thing I have noticed with some agencies radios is that they do not have the radios setup properly after they get them. All BK radios since the KNG series came out require you to populate a zone and channels within those zones by using the Radio Editing Software when you create your code plug. "Accept Incoming Clone" feature also has to be selected in RES for those zones you wish to be able to accept an incoming clone into your radio.
Older radios like the D, G, E series and so on did not require this setup to be able to accept a clone, only the Accept Incoming Clone feature was the main issue you ran into with those radios other than cloning cable and series incompatibilities. For example, the D Series radios (DPH, DPH-CMD, DPHx) all had 25 zones from the factory with either 16 or 20 channels in each zone depending on if it was a Command Version or not. You could not add or delete zones or channels in those radios. With the newer radios you can have almost any number of zones and channels within those zones that you want but you have to have them programmed in the radio by using the software.
What I recommend you do is create 3 dedicated Clone Zones in your radios (the last three zones) and populate those three zones with at least 20 channels in each zone. 3 clone zones is the most I have ever needed while deployed on incidents and having at least 20 channels in each zone allows you to get all of the channels from an incident clone from the incident COMM Unit.
From my experience most of the COMM Units will develop a radio plan for the incident and make it 20 channels. If they do it this way then the people with older 20 channel command version BK's can take the same clone as a standard 16 channel version radio. The incident com plan sheet may just show 16 channels on it in the IAP but most clones I have gotten have 20 channels in the clone.
I would also recommend that you create at least one COMMAND ZONE in your radio and learn how to use the command zone feature. It is very helpful when there is no clone available and you have the needed channels somewhere in your radio already or you need to edit an existing incident clone on the fly.
You will have to create a zone in RES, designate it as a command zone, select a menu option or a programmable button as your Channel Add/Delete ( I like to assign the star key on the keypad or the emergency button as the Channel Add/Delete) and then your done.
Note: You do not have to add channels in a Command Zone in RES when you create the Command Zone. To delete all channels within a Command Zone you will press and hold down the Channel Add/Delete button to give you the option to delete all channels in the zone.