Frank, Ernest, and Dewey Denouement would have ended up on different sides of the schism since childhood?
The triplets were recruited when they were five years old. What if they'd each somehow been recruited into different sides of the schism?
Frank was recruited by the firefighters.
Ernest was recruited by the firestarters.
And Dewey...
I read a theory once that there are actually three sides of the schism: the firefighters, the firestarter, and the neutral side. For instance, in the theory Olivia Caliban was on the neutral side of VFD, which is why she freely gave information to any firefighters and firestarters who asked. This neutral side of the schism is the side that recruited Dewey.
This, of course, leads to even more confusion, as no one on any side knows that there are two more Denouements than they know.