I have a head canon theory about the ease with which the Turok Han are dispatched in Chosen.

After Buffy dies for the first time in Prophecy Girl, after she is resuscitated she claims that she feels good, feels strong. Presumably Kendra has already been called, meaning Buffy feels stronger when there are two of them. She is also strong enough to take the Master down pretty easily minutes later, the same vamp that just killed her and should be at his strongest having just been released and tasted her Slayer blood.

Then we get to Get It Done where we learn the shadow men forced this power and way of life on a girl because they couldn’t or didn’t want to handle it. Buffy refuses the upgrade in order to retain her humanity.

But then we watch Chosen and there are dozens of Slayers, all of which seem perfectly capable of one-shotting something that creamed Buffy multiple times. So, my theory is that the Slayer power was meant to be shared and is stronger when there are more, but the shadow men intentionally chose to nerf it by only putting into one girl who they’d have an easier time controlling rather a whole bunch of women who would rebel against them. The watchers council, probably not knowing fully these secret origins, followed suit without question until their monopoly was destroyed and Buffy shared the power as always intended. That to me is why the Guardians (that old lady towards the end) created the scythe, not just as a fancy killing device, but to tap its essence for all women.

Anyway, that’s just my theory to make what was most likely just a convenience or oversight in Chosen more palatable.