You're reliable source is correct, as is the official CAL FIRE Radio Call Plan(s) that get leaked to the internet every year or two.
All of the CDF Command channels with the exception of Command 1, Command 2, and Command 11, are assigned to a specific CAL FIRE unit/multiple units for repeater access. Command 1 and Command 2 can generally be accessed statewide for repeater access.
Command 12 (and still technically the old Command 5) are assigned to TCU only.
While outdated, this Radio Call Plan from 2011 is the better one out there in my opinion, as it shows the map of the different Command channels and their usage throughout the state:
http://www.calfireslo.org/Documents/ECC/2011 Radio Call Plan 6-2011.pdf
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