It's a good question you ask. Back around early 2011 ish before those tweeners were released, we just called them tweeners and described each individual of the 3 knives by the blade type, Drop point tweener, clip point tweener & trailing point tweener. That was before they had a number associated with them.
I guess now when I call them tweeners I'm referring to the handle size as compared to that Iconic full size Becker Grip.
As I recollect there were 4 or 5 prototype Tweeners which were being considered for production, one was a recurve fighting type knife. There's picture's somewhere.
Is recurve even a knife term or am I mixing up some Archery terms? It's late and I'm old, and fat too, don't forget that.
Tweener!