One way to prevent a fight scene from being slowed down is to enable the reader to come to it with some _prior_ knowledge of the way things will go, so that somewhat less description will be needed _during_ the combat. In my "Tigers" novel, on or around Page 54, the Talking Tigers were preparing (with human allies) to fight a gigantic quasi-reptilian monster from the sea. Here is how they discussed what they would do....
"All the way back here," Slimtalon replied, "I was wracking my brain to remember everything the Sea Otters reported about my husband's last fight. I remembered that the monster has a great long tongue that can grab you; I remembered that in time for the knowledge to help my son. Since then, I've also remembered that the monster has a line of sharp quills or spines all along its back, like sheathed claws, which can spring up to stab any creature who climbs onto its back. Brightburn was gravely wounded by those quills when he leaped onto the monster's back. But the missing pawprint in this trail still evades me. There was something my husband did as he was dying, which hurt the monster so painfully that it gave up on chasing the otters even _after_ Brightburn was no longer a threat to it. This makes me feel as if I'm the very first Narnian beast to grow so old as to lose my brains; I just can't _remember_ what it was!"
"Don't reproach yourself, Grandmother," said Smoothtail. "You've carried so many responsibilities in all those years, and no one could have predicted that now you'd be trying to remember the details of an event that you weren't present for!"
"Let's just list everything that _could_ be a weak point on a creature like that," said Shatterneck.
Slimtalon replayed in her mind the terribly recent chase in which the unwelcome role of quarry had been hers to experience. "One would expect its eyes to be a soft spot, but Bulgak found otherwise when he shot the thing in the eye. The nostrils proved subject to pain, but only on the inside."
"That snatching tongue you described is a weakness as well as a weapon for the monster," mused Quickspring. "If it were severed, the stump would bleed spectacularly. And then there's the axillae--"
"The what?" asked Leapwell.
"Sorry, that's an anatomical term I picked up from a Centauress. It just means the inner parts of joints--like a man's armpit. Places that have to be less rigid, or else the joint wouldn't be able to flex at all. Hookpaw got hold of such a spot on that crocodile he helped me fight. Our adversary must have axillae, since it has limbs. We might be able to get at those--or maybe one of the Djinni could, with a weapon."
"The Djinni felt sickened just from being near the stink of it," said Slimtalon.
"But not incapacitated, or they wouldn't be here," Quickspring persisted. "If any of the Djinni could get close for just an instant, he might be able to drive in a spear. We could help make his opening if we could force one of the monster's limbs up to expose its axilla."
"Failing that," interjected Tawnydart, "maybe we could create a weak spot elsewhere. Scales on reptiles and fish usually aren't attached all the way around; they have an outer end, like a human fingernail. Maybe we could get hold of the ends of some of the monster's big scales, and pry them up. It wouldn't need much opening for a spear to penetrate."
"Or a bullet?" said Smoothtail. "You said that the boy has one of those shooting weapons."
Slimtalon shook her head. "No, Bulgak has done enough; we can't ask more of him. He must take his mother and the other children and go with Hookpaw to the new colony. Let him be a defender to them on the way with his rifle."
"But prying up the scales may still work," said Leapwell.
Slimtalon visualized the effort of prying loose those iron-like reptilian scales. Whoever was doing the prying would need lots of protection, but it might work...
Then, as this image grew sharper in her mind, she pounced on a realization. "That's it! That's it! Oh, Brightburn, my love, you _shall_ be avenged!" All eyes were on her as she continued: "It has GILLS as well! THAT'S where my husband struck back at his slayer: he tore at its gills! The gill-flaps would be at least as easy to pry up as the scales, probably far easier to lay hold of; and almost any wound inflicted inside there would sever some blood vessels!"
"Hurrah for you, Grandmother!" exclaimed Shatterneck. "We'll get the filthy thing now!"
Slimtalon grew solemn again. "But consider this: any tiger attacking the monster's gills will be within reach of its foreclaws. That didn't matter to my beloved; he was dying already, with nothing to lose. It was enough then for him that he saved those Otters. But I don't want any of us to die needlessly. So don't attack _only_ the gills; the scale-prying and joint-biting are still worth trying also. Take whatever opening Aslan's providence grants us; but I believe that the gills will be decisive."
"Right," growled Quickspring with guarded optimism. "We'll form three teams, to attack the monster from three sides. Grandmother, your son and your daughter-in-law are the natural ones to fight beside you; and I'll trust them not to let YOU throw your life away needlessly. Shatterneck and Tawnydart are another natural team. Leapwell and Smoothtail, you'll be with me. If the Djinni can spare one of their number from their dealings with our human foes, he can operate independently, watching for his chance to exploit any opening we create...."