@curiousdannii "Or is this your point..."‌​. Yes. ;) That captures it nicely! (Sorry - forgot to reply earlier.)

@Dɑvïd Okay. Well I'm not sure exactly how well supported that statement is, but I think it might be broadly accurate. However the bigger point is that it's talking about diachronic fluidity. I understood your original comment as referring to synchronic fluidity. In a synchronic analysis (as we do most of the time for the Biblical texts) I would say that morphology and syntax would be as fluid as each other.

I think that when we see unusual syntactic constructions most of the time it's because we don't full understand the pragmatics and discourse conventions, not because syntax is inherently more flexible than morphology.