urochimaru summons the first and the second and takes out his ksanagi with long range, summons manda and becomes the yamata no jutsu beast.
itachi tries tsukiyomi which probably doesnt work, he does amaterasu on a couple of bodies and the landscape, which may or may NOT be deiverted with shinra tensei, then finally releases susano which im pretty sure cant be diverted with shinra/chibaku. and im not sure who or what it wud seal if it touched one of pain's bodies, but its probably that hell pain wudnt be able to bring their souls back from the dead aftyerwards.
jiraya summons gamabunta and the other big toad, turn to sage mode, and starts out with his wide rang attacks, toad oil blast and ultimate raasengan as well as the genjutsu that got pain the first time.
tsunade summons her slugg to heal everyone and joins the fight with her self healing and strength
diedara makes birds/mies etc and creates c-3 and c-4 through the air against where pain is. if needed he can do his suiocide jutsu at moment's notice
sasori takes out his 100 puppets as well as yondaime kazekage who can control the iron sand and attacks all of pain's bodies.
kakuzu is just using long range proijectile like attacks
hidan is a useless arsehole
kisame we dont know enough about, but he atleast creates a lake of water and geyser+ sharks to atttack. and ofcourse, his chakra eating sword/strength/huge chakra reserve helps a lot.
im sure pain cud kill a lot of them, but against that type of onslaught, can he really win? im not sure. possibly, since his range of jutsus alone is probably compareably to more than half of them combined, but this is too hard to call.
Except Sho and Ni need a bit of prep to summon, and wasn't the point of Saru sealing them was so they could never be used that way again? Manda is as useless as Gamabunta. And Yamato No Jutsu would probably fair just as well.
So he tries three things that don't work to stop Nagato..all before Nagato can use his nearly instant attack? Three nearly instant attacks are slower than one and if he uses Susanoo last he won't get to it. And Amaterasu < Absorbing Pein.
Gamabunta, and them = useless...In case you didn't read the manga. His Sage Mode didn't help him out last time and Pein didn't even use any of his major attacks. Any attack Jiraiya uses < Absorbing/Deva Pein. And the genjutsu takes time which he won't have.
To do that takes a bit of prep because she was using he chakra to heal, being carried around by Katsuya. She'd be out of the fight. and the slugs still couldn't help everybody from not being injured even after Tsunade put all he chakra into trying to save them.
All which are still much, much slower than the Shinra Tensei that will be needed to take Deidara, and the others out. Now if Pein tries Chibaku Tensei you have a point..but he doesn't need it.
Which does nothing because they are dead and his whole poison ability is useless, and his puppets are destroyed by Shinra Tensei..though he may be one of the only survivors afterwards but he won't have a body.
Which does nothing as Absorbing Pein is around if they somehow get threw as his attack will be deflected by the Shinra Tensei coming to beat everybody at once.
And the only other survivor besides Sasori..until Pein stabs Sasori's heart, which will be all that's left after Shinra Tensei destroys his body and puppets.
Creating a lake against Ninja who are dead/walk on water isn't helpful. And his shark attacks are useless against people who absorb chakra or deflect attacks..And his huge chakra won't help him against Shinra Tensei.
Not really hard at all. None of them can stand up to Shinra Tensei, and even fewer will be able to survive. Oro, and Hidan will probably be the only living ones left because Oro is so hard to kill, and Hidan is immortal. Sasori will survive the initial onslaught of Shinra but he's dead as soon as Pein stabs his heart.
__________________ If you try something stupid, and it works it ain't stupid.
^but your considering all of them attacking him seperately.when in reality they are all attacking at once.
all summones, tsukiyomi/jiraya genjutsu, amaterasu/susano/yamato no jutsu/kusanagi/first and second hokage/world model iron sand/long range fused elements/c-3/c-4/suicide diedara/watrer jutsus and chakra absorbtion of kisame/and all the other characters charging at the same time.
No I'm thinking of them all attacking at once..Or as much as they could. Attacking at once would make them loose a whole lot of power actually. And would still be useless as it would all be blocked by the Shinra Tensei that would be coming to beat them. And most of the attacks you named are slower to use than Shinra Tensei is to use. And the First and Second Hokage are not usable in this battle. It takes a lot of prep to use that...And Saru sealed them inside the death god so they wouldn't be used like that again. So even if Oro wanted it would be impossible to do.
And Suicide Deidara would end up taking out his whole team also...But it's still slower than Shinra Tensei...And..Nagato still wins even if it isn't as everybody is dead because Deidara was stupid and killed them all. Where as Pein would just make them all down and out.
__________________ If you try something stupid, and it works it ain't stupid.