as far as my mediocre writing skills go, I try to keep conversations limited to ONLY 3 guys. If more, I'd send the others to be BG charas (Tom ducked away to sharpen his machete) or just straight up NOT include them in the convo, and only mention them once or twice ("Ain't he a faggot," Sam said as he nudged a finger towards Tom).
But if you're insisting on keeping more than 3 charas in a single convo, the best thing to do is to determine who has the most say in the subject and who else can chime in an opinion or two.
So here's a quick example: the scene is in a rundown shack in a zombie apocalypse, Tom knows all about zombies, Sam doesn't know tad shit about zombies, Alex seen some zombie movies and Jesus is a gun nut. They're stuck in the shed and Sam doesn't wanna stay there.
"So what, we're just gonna sit out here until the sun comes up," Sam rattled, "might as well hang an all-you-can-eat buffet sign over the damn door!"
"Sam's right," Alex said, "we can't just sit out here and wait."
Tom drew his wrinkled face towards the motley group, his signature disdainful expression hung over his cheeks like a paint to a wall. "No," he said before going back to sharpening his machete.
"No worries, though," Jesus chimed in from behind, polishing his Beretta for the twentieth time today, "if they want a buffet they can have these condiments." He drew up a fistful of gleaming 9mms before going back down.
"Yeah, they'll definitely enjoy human meat with a dash of Italian metal, Bible man," Sam snorted, "I've seen those fuckers out there. I've seen what they've done. They can fucking smell us from miles away. Yeah sure, we have walls, but for how much longer."
"Surely you have some ways to get us out of here, right?" Alex pleaded with her oh-so-supportive customer support voice. Seems like it still had some use, even when the world's gone to shit.
"In, and that's final." Tom didn't even look back as he said his words.
"At least we can board the windows so that they won't see us-"
"Board what?! So we can slowly pry it back out when they crash in the walls?!" Sam stood up, his hair on his edge.
He couldn't take it. Five hours into the apocalypse and all God did was give him a girl in a blouse, a guy who can't gun for shit and a cooky old man who claimed he time traveled from the Third World War to stop said apocalypse, which judging by the now, had failed as spectacularly as anybody would've ever imagined.
Alex grabbed him by his torn jeans, "Pipe down, you're gonna attract atten-"
"Like the fucking lamp didn't?!" Sam shot a finger to the oil lamp sitting beside Tom.
"Shut up! You're ruining my concentration! I can't get the spring lock in," Bible Man spat out from behind.
That was it, Sam thought. That was so it. Twenty-two years he'd live and ten out of those twenty-two he'd dedicated his life to the church and the God's book and this is the way He thanks him - by sending him to hell in a handbasket.
"Fuck, fuck, FUCK," Sam spat out in a fit of rage. Alex wouldn't dare to shout him down, fear that the already booming voice would call out the undead. Jesus was rubbing the hell out of his magazines in grunts. Tom stayed as if nothing's happening behind.
Sam lunged his legs out of Alex's grasp and stormed towards the wooden door. He slammed his hand on the doorknob and swung a finger towards the three. "At least if I fucking die, it's not with the three fucking stooges-"
THUNK
- was the sound that shut everything up, as if it was a mute button to the whole world.
A machete, wobbling from its plastic handle was lodged right between Sam's head and hand with perilous inches in between.
Alex only watched in silence as the machete did the last of its dance. Even Jesus slammed the brakes on his firearm maintenance, watching Sam stand rooted to his blood-stained Nike kickers, not daring to see the gleaming, rusted metal beside his head.
Tom's arm was outstretched, bulging and shaking. The old man shot up from his seat and strolled across the room, pulling his machete out from the door. Nobody dared to move a single muscle.
For the entire time, Tom's face stayed the same; a frown over a controlled breathing, as if he hadn't attempted first-degree murder with a flying machete mere moments ago.
"Open the door, and you open the doorway to Lucifer. I was sent back to retrieve you - all three of you, so that when I go back, the streets won't smell like Hannibal's asshole. I don't care whether you like it or not, you stay right here in this very room. Dim light deters the dead, and they're all deaf. Shout all you like and they'll still strut along. What they can do, is smell. More you move, more you sweat. You already smell like a gas chamber, so this light is the only thing keeping you alive."
Tom strut back to the oil lamp and, like nothing happened, went back to sharpening his blade.
"I pulled you out of that trailer to keep you alive. I'm not risking your idiot anger management ass back out there so you stay put here, or you're gonna wish it was the zombies and not me."
He turned back for the last time, staring at the shellshocked, panting Sam.
"I won't miss the second time. Sit down."
Alex gathered every last courageous breathe she had. "Tom got us out of there and lost the zombies. Himself. Listen to him. Maybe what he's saying is true. We're still alive, right?"
Jesus agreed, "Old man pulled us out of trouble in a five minutes when it took us five hours. If it's his bullshit that saved us, I'm sticking to that shit."
Sam darted his eyes across the chick and the gun nut. He took a glance to Tom, his broad, wounded back still bent, sharpening the blade that mowed down the horde they've so desperately tried to outrun and failed before he came in.
"Fuck."
Tom is the pivotal guy, while Sam is the convo carrier. Alex acts as a support while Jesus just does his own background work. Give them their own roles so it wouldn't be confusing. Name drop the characters as much as their dialogues so that the readers can have a good sense of who's having a bigger role in the convo.
Take my word with the smallest grain of salt you can find. I don't have any credibility or example to back my words other than what's up there. You're welcome, if it'd helped you any.