Is this a typo in The Call of the Wild?

Here is the scene of the final fight between Buck and Spitz at the end of chapter 3 in The Call of the Wild by Jack London:

Spitz was untouched, while Buck was streaming with blood and panting
hard. The fight was growing desperate. And all the while the silent
and wolfish circle waited to finish off whichever dog went down. As
Buck grew winded, Spitz took to rushing, and he kept him staggering
for footing. Once Buck went over, and the whole circle of sixty dogs
started up; but he recovered himself, almost in mid air, and the
circle sank down again and waited.

But Buck possessed a quality that made for greatness—imagination. He
fought by instinct, but he could fight by head as well. He rushed, as
though attempting the old shoulder trick, but at the last instant
swept low to the snow and in. His teeth closed on Spitz’s left fore
leg. There was a crunch of breaking bone, and the white dog faced him
on three legs. Thrice he tried to knock him over, then repeated the
trick and broke the right fore leg. Despite the pain and helplessness,
Spitz struggled madly to keep up. He saw the silent circle, with
gleaming eyes, lolling tongues, and silvery breaths drifting upward,
closing in upon him as he had seen similar circles close in upon
beaten antagonists in the past. Only this time he was the one who was
beaten.

There was no hope for him. Buck was inexorable. Mercy was a thing
reserved for gentler climes. He manoeuvred for the final rush. The
circle had tightened till he could feel the breaths of the huskies on
his flanks. He could see them, beyond Spitz and to either side, half
crouching for the spring, their eyes fixed upon him. A pause seemed to
fall. Every animal was motionless as though turned to stone. Only
Spitz quivered and bristled as he staggered back and forth, snarling
with horrible menace, as though to frighten off impending death. Then
Buck sprang in and out; but while he was in, shoulder had at last
squarely met shoulder. The dark circle became a dot on the
moon-flooded snow as Spitz disappeared from view. Buck stood and
looked on, the successful champion, the dominant primordial beast who
had made his kill and found it good.

In the last paragraph, after "Buck was inexorable.", who maneuvered for the final rush?

If it means that Buck maneuvered for the final rush that would finish Spitz, then, as it is written later on, why would "their eyes" be fixed upon him? "their eyes" should instead be fixed on Spitz, as he is the one about to be killed.

And if it means that Spitz maneuvered to get ready for the final rush, shouldn’t that bold part later, then read "beyond Buck and to either side…"?