I’d give the most focus to the most important fight. If your MC/ POV character is engaged in a fight, they could notice things going on in the fights around them (assuming all are ocurring in the same location). Sneak in those observations as the action is going on.
Ex. I heard the scream of Mega as she was thrown against the brick wall. I had only enough time to glance over to see her slumped body before my own oponent took advantage of my hesitation, kneeing me in the stomach. The air was sucked out of my lungs, and I fell to the dirt-packed ground.
Immediately, calloused knuckles met my nose, sending an explosion of pain through my face. Black dots swarmed my vision. The powerful punch rocked me off of my knees, but I managed to get my legs underneath me and stumble sideways. Warm, sticky blood flowed down various cuts across my skin, and I felt the steady ache of new bruises.
However, I wasn’t sure if I could look any worse than Adrian. Only a couple of feet away from me, he had a rugged-looking thug pinned against a dumpster. Every punch he threw sent the metal box creaking. Despite his apparent upperhand, he rocked two black eyes, a swollen, purple cheek bone, and various gashes across his upper arms.
Shaking hair out of my eyes, my gaze caught on the glint of something in the sun’s rays. A beer bottle. A sharp kick to my mid back sent me skidding forward, gravel scraping my chin as I face planted. Rage bubbled through my veins. These people wanted to hurt my friends, possibly kill them. I was done holding back. Stretching out a dirt stained arm, I grasped the warm neck of the bottle. In one smooth movement, I stood up while twisting to face my enemy. The glass shattered and sprinkled his leather jacket like snowflakes as I smased it into his temple.