Dave,
I noticed that myself but never thought anything wrong of it, until now...here's why:
The use of simplex for fireground communications, barring any unusual situations like a high-rise building or multi-acre brush fire, is a "must." Yet Operations Centers and dispatch centers want to know what's going on in real time on a fireground - not wanting to wait for a progress report from the IC. One way that I've seen this accomplished by a number of suburban departments around the NY Metro area is to have everyone on the fireground operate on simplex - on a repeater input. This way fireground comms could be recorded back at OCs and dispatchers could continue to "buff" the job. The firefighters don't know the difference...they are still talking, on direct, from the hydrant to the pump panel, from the roof to the attic, etc., etc., etc., just like on a normal fireground channel, but the repeater is keyed every time - passing the traffic from the scene. When I saw the original channel plan, I just figured that was an additional option made available. But when you pointed out the input PL conflict between the primary and back-up repeaters.....hmmmm.
SCANdal