for the most part i do agree with you.
however, i can also imagine, priscilla missing in killing some of them too, which they then retreat and come back in full force "stronger" then before.
I can also imagine, Priscilla not realizing she needs to kill all of them, just like Riful didn't realize it (in the time she had, though it didn't matter as Priscilla took out Riful "for the AFs" anyways, lol), nor did Isley realize it in time. When Isley realized what was going on with the AFs, it was too late. They already had too much combat experience and knowledge about him, and he could barely hit and kill them anymore.
and to get extremely technical:
(if they were "programmed" this smart anyways)
they could always leave a single AF off a distance out of the fight in hiding....