You are mistaken. Command repeaters are only linked using UHF (406-420 MHz) frequencies. Different command repeaters allow more than one to be linked together and yet transmit all at the same time. The radio user chooses the repeater that provides coverage to the area of the fire they are in. That repeater then transmits to the area it covers. That VHF repeater is hard wired to a UHF transceiver. The UHF radio then transmits to a location that can receive the UHF signals from each of the additional command repeaters installed on the net. That location is often called the "hub." This central location has one UHF link for each of the VHF repeaters on the net. These UHF link radios are hard wired together. The signal received by any one of these UHF link radios is passed to the others on the hub. Each of the UHF link radios in the hub then transmits to the UHF link radio hard wired to each VHF repeater on the net.
Linking the VHF repeaters together with UHF links allows each repeater to transmit to all the rest, each of which utilizes a different VHF frequency pair. This allows the same signal to be transmitted on two or more repeaters at the same time. For example if there are four repeaters on the net, which we will call repeaters "A, B, C and D." When a radio using the repeater A frequency pair is transmited the signal is simultaneously transmitted over repeaters B, C and D at the same time. If each repeater used the same frequency two or more repeaters, each on the same frequency pair, interference would be experienced as two FM transmitters on the same frequency try to cancel each other out.
This differs from a forest, park or BLM district net where each repeater is chosen by the user by switching tones. All the other repeaters on the net use the same frequency pair so only one repeater can be used at the same time. The dispatcher can hear all the repeaters on the net, but again, only if one is transmitting at the same time. The field units within range of the selected repeater can hear whatever the repeater is "repeating," but can't hear some repeaters on the other end of the forest, park or district. If a forest wanted everyone on the entire forest to hear every repeater all over the forest, it would require as many VHF frequency pairs as repeaters, which for some forests in California numbers 16. There aren't enough frequencies available to do this.
Those using the command net on a large fire need to hear all the traffic on the net. This is why two or more repeaters need to be used simultaneously. This system of multiple repeaters and links is only used if one repeater can't cover the entire fire.
VHF repeaters are not linked using other VHF repeaters. The federal government does not use VHF frequencies to link radio sites, remote bases or repeaters. The UHF band is the only one used for linking.
I hope you can grasp all of this. It is easier to diagram radio networks on a white board than to write a description.