Actually, they don't sound at all like Morrison- they have American accents, while Morrison (and the clones) has an Australian one. I'm pretty sure the Visual Dictionary says they're not clones but that after the Clone Wars many clones became firefighters due to the need for softer work because of accelerated aging. So some firefighters are clones... from a certain point of view.

Of course those fire rexcue pilots were clones. Don't they wear outfits like regular clones do? To me, they did sound like Temuera Morrison. So they have to be clones.

Well, they didn't go to the Jedi Temple when it was on fire, so they could be clones.

Otherwise,.....Worst. Firemen. Ever.