I guess it depends on what the original inspiration was.
If the flyssa developed from the yataghan, then the shorter beefy ones came first and got progressively longer as other influences exerted themselves.
If it developed from a Circassian-type sabre, then the very long ones came first and got shorter as they transitioned to a foot soldier's weapon. My understanding is that the very short ones came last when the local Kabyle arms industry was shut down by the French, and the markets changed.
I consider these curved examples to be small, custom runs, deviating from the classical examples we know.
The fine art history student looks for a progressive development chain. In all forms of plastic arts you can follow development from an early prototype of some sort, progressing into something new. It's very difficult to see that in the flyssa. It seems to have just appeared, fully formed, like Athena bursting from Zeus' head
There's also the possibility of the older prototypes having been recycled as something else, or having been upgraded to the classical style. This would explain how the unusual flyssa can deviate in form but maintain the decorative scheme.
Lots of thoughts to sort out...