You know, I only just sussed out you can buy other perks weapons last night

MANDATORY: If you don't have these your chances go down the drain. You could still win, but I won't be betting on it. Are either vital for both bosses, or so vital for 1 boss that not taking it severely handicaps you if the wrong boss spawns.

1 Medic, level 20 or higher with Coagulant Booster and the rifle. Without it it is nearly impossible to deal with the potential damage output of Hans. It is heavily advised that you go all left. Symbotic Health will keep your own health topped off, give you your own buffs, and put you in the range where you can reliably take 2 melee strikes. Adrenaline shot allows players to sprint out of the bosses' melee lunge, and Coagulant Booster lets 100 health players survive 2 hits. Focus Injection is taken because poison is useless against the boss. Recommended off-perk weapons would be a katana to parry and a DBS to jump out of a boss's lunge.

1 tank Berserker with a tier 4 weapon and Parry. Dreadnaught is preferred because it lets you take 3+ melee strikes and gives the Medic a lot more HP to work with and apply Coagulant buffs. However, if you are confident in your parrying, you can take Skirmisher because the speed will let you chase down the boss when he tries to go after other players, or when Patty flees to heal. Bone Crusher is better for Hans because the block counters melee spam, while Eviscerator is better against Patty due to the ranged attack letting you chase him down more easily when he heals. Parry is the best skill for 1 on 1 melee duels, which is what the boss wave boils down to. A combination of the berserker native resistance, Parry active, and Coagulant can put your passive damage resistance up to 85%. Combined with blocks/parries the boss's melee will be doing less than 10 damage to you. The EMP grenade deactivates Patty's cloak.

TOP TIER: So good they're as close to mandatory as you can get without being 100% necessary. Are effective against both bosses even when stacked.

X number of Demos with RPGs and C4. Needs at least 1 spare RPG each due to ammo consumption. C4 can be attached to the Patriarch and will be visible when he cloaks. You see a levitating pile of blinking C4, no, the C4 didn't come to life, it's actually the Patriarch. Is also the best dps perk against Hans due to his weakness to the RPG, as well as the safest dps against Patty. Provides extra grenades for the medic. Buy a DBS in case it's Hans to use the recoil jump to escape his lunge, and a med pistol. His reactive armor also gives you a second life, letting you be more aggressive.

GOOD: Really good perks, but you're not going to be wanting multiples. Have valuable uses against both bosses, but due to diminishing marginal returns having a 2nd player of the perk isn't advised.

1 Support for dps, giving armor and ammo to players, and for killing the trash zed that spawn. Can also act as a secondary tank using the recoil jump from the dbs to safely keep the boss's attention. His reload speed with the DBS allows him to keep the boss' attention indefinitely as long as no projectiles are used. Can chip in damage against the boss with the AA12 and be a secondary medic with the HMTech-301.

Firebug. Arguably the best bodyshot dps against the Patriarch if not for the range problem making the microwave gun very risky. Still good dps against Hans. Can also clear trash. Heatwave is guaranteed to stumble both bosses if it isn't on cooldown. Hans is weak to fire, and dodges ground fire often enough that it becomes a reliable way of controlling his movement.

MEDIOCRE: Valuable on 1 boss in particular, or have deficiences that make it a risky take.

1 Commando to spot Patty if it's patty, and to kill the trash zed; it's not mandatory since a demo can stick C4 on Patty to make him visible anyways, and a Support with an AA12 can clear trash just as well.

Sharp: Needs headshots, damage skills require you to stand still and let the boss come closer. But with reload canceling, good aim, a good spot, and a team that knows how to distract the boss, you can contribute enormous dps. The freeze grenades can also immobilize Patty if 2 connect in close range, and give you a chance to kill him then and there. If you can consistently reload cancel the railgun this becomes Good/Top tier. If you can't do what I'm doing in the second half of this video, don't go sharp.

NO: Chances are that this is a idiotic pick. Has no special utility against either boss, or is heavily countered by one.

Swat: Bad DPS and no Patty callout. Flashbangs can't stun either boss unless you stack multiples directly under them, which is impossible due to the fuse timers spreading out the stun explosions as well as their massive stun resistance. SMGs are also less than adequate against the large number of gorefiends that spawn.

Gunslinger: You're gonna spend half the time reloading your .500s. Due to the small magazines the dps suffers due to being forced to constantly reload. Hans in particular hard counters the gunslinger due to his twitchiness and jetpack, which makes REM almost impossible to use, as well as the fact that his limbs are covered by a damage reducing armored exoskeleton, which counters Bone Breaker. Hans also has enough speed to chase down a gunslinger, making the speed advantage almost irrelevant since it only delays the inevitable. The only way I'll ever take this perk is if you are a human aimbot, and if you are a human aimbot, a reload canceled railgun is better.

Survivalist: Don't play survivalist.

The following are the biggest causes of failing the boss
Not having a medic with Coagulant Booster and the medic AR. It is almost impossible to out-heal Hans' damage otherwise.

Not having a tank perk to control the boss's aggro. Management of the boss's aggression is paramount.

Picking an bad area to fight the boss. Hans and Patty often require different arenas to fight in, because they are fundamentally different. Hans is a speedy melee unit, while Patty is a slower sniper.

Being out of position and getting trapped, getting caught with no nearby cover with the Patriarch, or getting clustered near Hans' explosive grenades.

Having too many low DPS or precision based perks or skills. You're not going to be hitting headshots on the boss that consistently, especially Hans. Swat, commando, gunslinger, and M14EBR sharp in particular are bad for the boss wave due to low dps and/or headshot dependence. Certain perks like commando, which are exclusively useful against only 1 boss, are also bad ideas.

Failing to deal with the trash zeds that come during the boss round. Everybody is shooting at the boss and forgetting about that one guy stuck in a corner with 2 husks and a bloat. Do not tunnel vision on the boss. Keeping the team alive is the top priority, not a little bit of extra damage.

Not parrying the boss's melee attacks.

Leaving a player to fight the boss alone.