Could Bivol or Beterbiev last 12 rounds with Joshua?

Running around a 22 foot ring and throwing themselves to the ground? Yes they could. But they wouldn't, because they are boxers. Anyone claiming Paul 'lasted ' 6 rounds didn't watch it. He lasted zero rounds of actual fighting.

More so Biv But AJ would eventually get them both out

185 pounds Top Soviet Bivol next to a super heavy and cruiser Parker is 260+ on fight night while Jai be a good 220? {"data-align":"none","data-size":"full","src":"https:\/\/scontent-sea1-1.xx.fbcdn.net\/v\/t39.30808-6\/489815171_1127965989349150_1489677139592338370_n.jpg?_nc_cat=108&ccb=1-7&_nc_sid=833d8c&_nc_ohc=k7UWWgN_aBEQ7kNvwE4LCpC&_nc_oc=AdkMhRl1Dcj5Q7K3X6ztupK9PaVMHkKCe8PMcZuRQ2d82caqWXgcolentNtO5B1RFWB_1yFTDrfTdHw7WE8bzo_s&_nc_zt=23&_nc_ht=scontent-sea1-1.xx&_nc_gid=aLTgjXhKK9snjqueM8evwg&oh=00_AfkJoez-_dqvEqeoGvHMMmwrRhblhI-NslE2Oj0aSCgFvQ&oe=694C099B"}

Josh would have a good 50 or 60 pounds over each of these guys

Top Soviet Bivol who isn't known for power hurt Artur with a hook in round 7 of fight 1 Artur chin wouldn't hold up v heavies

or Parker's Cousin Buff Guy Jai and Fat Dave

Probably. Especially Bivol with his movement. Beterbiev could probably hurt Joshua but he's also 40. But both Beterbiev and Bivol wouldn't be pulling a Rigondeaux in the ring like Jake did. They'd actually engage and try to win rounds, so who knows. I wouldn't bet on either of them actually winning the fight, although I could see their winning a points decision if their plan worked perfectly.

I think Bivol has the savvy to go 12 and could even win a decision. Beterbiev has a chance to stop AJ or get stopped himself.