OK, so nobody knows anything and what you do know is wrong. Statements like "he needs to check current information" are not helpful. He does know all the the frequencies you refer to and he has a more up to date list than the one you posted. Its just that the fire camp frequencies are portable repeaters. They would not normally be used except at a major fire and maybe not then. They might use other NIFC frequencies. The thing about these lists is that they don't always mean that they will be used - just that they can be used. Sometimes they're just plain wrong.
Whether or not dual inputs are a good idea is debatable. Maybe someone pushed the wrong button on the console.
By the way, I do have actual public safety radio experience and so does my source.
I am just reporting observations. If they don't make sense then they don't make sense.
My late Hubby never went to a fire camp where the Service Net is put on portable repeaters. If Service Net repeaters don't cover a particular incident command post it is possible for them to install a portable remote base station that would link the ICP with UHF frequencies and have a Service Net input as the VHF output of the base. We never observed this happening, but I can see that as a possibility. A portable Service Net repeater is not something that ground or air resources would use. Service Net is used for dispatcher to ICP communications, not field units to ICP comms. Sometimes a forest will use service net as an alternative, they might put command for a fire on it, they might change an entire ranger district to Service Net to keep folks off the other nets, that are busy with fire traffic. This is why it is good for them to have a good coverage Service Net system in place. Where Hubby and I lived we could hear 4 national forests and we listened to how they operated.
Where did you get the information or idea that Service Net is all done with portable repeaters? I just looked through the R5 frequency guide for 2020 and more than half the forests list a service net that is in their common group forest or district groups, all with permanently installed repeaters. The remaining forests might have Service Net in other groups that have large incident frequencies in them. Forests with district and management area nets don't nave a Service Net, this is the case on the Shasta-Trinity and Klamath.. The term "fire camp" is not actually current terminology, it is a throwback from the days prior to ICS. It has been replaced by "Incident Command Post," ICP.
In camp communications are conducted by simplex on UHF frequencies assigned to NIFC. A lot of firefighters don't know this as they are not carrying UHF radios and don't know the entire range of what the NIFC system does. There are 5 camp frequencies listed for the NIFC system. There are 7 logistics, temporary repeater frequency pairs. These can be used if simplex doesn't cover the camp, or if there is a receiving/distribution center some distance away from the ICP. There are 8 UHF frequencies for linking aviation frequencies, usually a VHF-AM remote base. There are 7 frequency pairs for linking command net, VHF repeaters. I'm taking this all out of the NIFC system user's guide.
My dear late husband carried a hand held scanner on all the wildland fires he went to when our local department sent Type 1 engines to fires. He had all the NIFC UHF frequencies programmed, figured out how the NIFC system worked and how forests used their systems when a national management team was not involved, the so called "Type 3 incidents" that have local people on the management team. We sometimes parked near a fire and he listened to all of the frequencies being used on the fire, no matter how obscure they seemed.