Round 1 goes to Killer be 10/10. Doesn't really matter that he can't use bijuudama, since his chakra cloak V1 or V2 is enough for this crowd. They're hella durable and offensive as shit. A lariat from him in these forms is busting Hidan open like a tin can and killing any of Kakuzu's hearts. Doesn't help neither of them have shown the offense to get around a V2 cloak.
Round 2 is much more interesting....
In character, against 2 opponents? Bee is using CQC with raiton chakra to gauge them immediately. Means he's vulnerable to being cut. Hidan will never hit Bee. Ever. Sasuke with the sharingan >> Hidan. And Sasuke was being tossed around. Kakuzu, however? Kakuzu has a chance at injuring Bee early on in taijutsu or getting possibly a raiton: gian off on him.
Basically, the only way they win round 2 is if Kakuzu injures Bee before Bee uses his chakra cloak on them. That blood lets Hidan murk Bee while Kakuzu holds him off. Still, Killer Bee wins it 7/10 times.